Generic Routing Encapsulation

Generic Routing Encapsulation (GRE) is a tunneling protocol developed by Cisco Systems that encapsulates a wide variety of network layer protocols inside virtual point-to-point links over an Internet Protocol internetwork.

GRE encapsulates a payload, that is, an inner packet that needs to be delivered to a destination network inside an outer IP packet. GRE tunnel endpoints send payloads through GRE tunnels by routing encapsulated packets through intervening IP networks. Other IP routers along the way do not parse the payload (the inner packet); they only parse the outer IP packet as they forward it towards the GRE tunnel endpoint. Upon reaching the tunnel endpoint, GRE encapsulation is removed and the payload is forwarded to it’s ultimate destination.

IPv6 over IPv4 GRE Tunnels

IPv6 traffic can be carried over IPv4 GRE tunnels using the standard GRE tunneling technique that is designed to provide the services to implement any standard point-to-point encapsulation scheme. As in IPv6 manually configured tunnels, GRE tunnels are links between two points, with a separate tunnel for each link. The tunnels are not tied to a specific passenger or transport protocol but, in this case, carry IPv6 as the passenger protocol with the GRE as the carrier protocol and IPv4 or IPv6 as the transport protocol.


Note

In Cisco ASR 901 Series Routers, for the IPv6 traffic over GRE, IPv4 is used as transport protocol.

GRE Tunnel Keepalive

The GRE Tunnel Keepalive feature provides the capability of configuring keepalive packets to be sent over IP-encapsulated GRE tunnels. You can specify the rate at which keepalives will be sent and the number of times that a device will continue to send keepalive packets without a response before the interface becomes inactive. GRE keepalive packets may be sent from both sides of a tunnel or from just one side.

QoS Tunnel Marking for GRE Tunnels

The QoS Tunnel Marking for GRE Tunnels feature introduces the capability to define and control the quality of service (QoS) for outbound customer traffic on the IP node or router (both encapsulation and decapsulation) in a service provider network.

If the service policy is not associated with the GRE tunnel, the QoS information from original header is copied to the outer header of a GRE tunneled packet.

If the service policy is associated with the GRE tunnel, the QoS information in the outer IPv4 header of a GRE tunneled packet is set as per the configured service-policy and table-map rules. If table-map rules are not configured for some QoS values, the outer header uses the value 0 for QoS fields in the outer IPv4 header.

Restrictions

The following are NOT claimed to be supported, though the configuration is accepted silently.

  • Termination of GRE with outer IPv6 header.

  • Multiple GRE encapsulations and GRE terminations.

  • GRE encapsulation followed by MPLS encapsulation.

  • GRE encapsulation followed by MPLS label lookup.

  • MPLS encapsulation followed by GRE encapsulation.

  • GRE termination followed by MPLS label lookup.

  • MPLS label lookup followed by GRE termination.

  • Support of VRF (MPLS) over tunnels.

  • Multicast GRE (MGRE).

  • MTU configuration over L3 interfaces is defined with the additional tunnel header length. This is because of GRE tunnel using the L3 interface for reachability.

  • Shaping and Policing support over GRE Tunnel Interface (logical interface).

  • Load-sharing is supported only for a maximum of two GRE tunnels.

  • GRE tunnels with same source and destination are not supported.

  • GRE over MLPP/PPP is not supported.

  • Both IPSec and GRE on the single node are not supported. That is, the following are not supported on the single ASR901 node

    • GRE encapsulation followed by IPsec encryption.

    • IPsec decryption followed by GRE encapsulation.


Note

You should remove and reapply the policy-map associated to an interface after any dynamic change or modification to the table-map.

Configuring a GRE Tunnel

Perform this task to configure a GRE tunnel.

Procedure

  Command or Action Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface tunnel number

Example:

Router(config)# interface Tunnel l00

Enters tunnel interface configuration mode. number is the number associated with the tunnel interface.

Step 4

tunnel ttl hop-count

Example:

Router(config-if)# tunnel ttl 5

(Optional) Configures the Time-to-Live (TTL) hop-count value for a tunnel interface. The default TTL value is 255. It can be changed using this command, which allows you to set the TTL value for the outer IP header of the GRE tunnel packets.

Step 5

ipv4 address ipv4-address subnet-mask

Example:

Router(config-if)# ip address 1.1.1.2 255.255.255.252

Specifies the IPv4 address and subnet mask for the interface.

Step 6

tunnel source type source-ip-address

Example:

Router(config-if)# tunnel source 11.1.1.2

Specifies the source of the tunnel interface.

Step 7

tunnel destination ip-address

Example:

Router(config-if)# tunnel destination 10.1.1.1

Defines the tunnel destination.

Step 8

keepalive [period [retries]]

Example:

Router(config-if)# keepalive 10 3

(Optional) Defines the keepalive period (default is 10 seconds) and the number of times that the device continues to send keepalive packets without a response before bringing the interface down.

What to do next

Repeat the steps on a different router to complete the tunnel configuration.

Ensure that tunnel destination should be reachable from source. And tunnel src, tunnel destination on encapsulation and decapsulation should match as illustrated below.

Encapsulation 


Tunnel src 11.1.1.2
Tunnel dest 10.1.1.1

Decapsulation 


Tunnel src 10.1.1.1
Tunnel dest 11.1.1.2

Configuring a GRE Tunnel for IPv6

Perform this task to configure a GRE tunnel.

Procedure

  Command or Action Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

ip cef

Example:

Router(config)# ip cef

Enables Cisco Express Forwarding on the router.

Step 4

ipv6 unicast-routing

Example:

Router(config)# ipv6 unicast-routing

Enables the forwarding of IPv6 unicast datagrams.

Step 5

ipv6 cef

Example:

Router(config)# ipv6 cef

Enables Cisco Express Forwarding for IPv6.

Step 6

interface tunnel number

Example:

Router(config)# interface Tunnel l00

Enters tunnel interface configuration mode. number is the number associated with the tunnel interface.

Step 7

tunnel ttl hop-count

Example:

Router(config-if)# tunnel ttl 5

(Optional) Configures the Time-to-Live (TTL) hop-count value for a tunnel interface. The default TTL value is 255. It can be changed using this command, which allows you to set the TTL value for the outer IP header of the GRE tunnel packets.

Step 8

ipv4 address ipv4-address subnet-mask

Example:

Router(config-if)# ip address 1.1.1.2 255.255.255.252

Specifies the IPv4 address and subnet mask for the interface.

Step 9

tunnel source type source-ip-address

Example:

Router(config-if)# tunnel source 11.1.1.2

Specifies the source of the tunnel interface.

Step 10

tunnel destination ip-address

Example:

Router(config-if)# tunnel destination 10.1.1.1

Defines the tunnel destination.

Step 11

keepalive [period [retries]]

Example:

Router(config-if)# keepalive 10 3

(Optional) Defines the keepalive period (default is 10 seconds) and the number of times that the device continues to send keepalive packets without a response before bringing the interface down.

Step 12

ipv6 address ipv6-address subnet-mask

Example:

Router(config-if)# ipv6 address 35:35:35::1/64

Specifies the IPv6 address and subnet mask for the interface.

Step 13

ipv6 enable

Example:

Router(config-if)# ipv6 enable

Specifies IPv6 processing on an interface that has not been configured with an explicit IPv6 address.

What to do next

Repeat the steps on a different router to complete the tunnel configuration.

Ensure that tunnel destination should be reachable from source. And tunnel src, tunnel destination on encapsulation and decapsulation should match as illustrated below. For IPv6 also, the tunnel source and destination (outer transport) should only be IPv4.

Encapsulation 


Tunnel src 11.1.1.2
Tunnel dest 10.1.1.1

Decapsulation 


Tunnel src 10.1.1.1
Tunnel dest 11.1.1.2

Configuring VRF-lite in Global Configuration Mode

Perform this task to configure VRF-lite in global configuration mode.

Procedure

  Command or Action Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

vrf definition vrf-name

Example:

Router(config)# vrf definition vpn_1

Configures a virtual routing and forwarding (VRF) routing table instance and enter VRF configuration mode.

Step 4

address-family ipv4 unicast

Example:

Router(config-vrf)# address-family ipv4 unicast

Specifies the IPv4 address family, and enters address family configuration mode.

Configuring VRF-lite for IPv6

Perform this task to configure VRF-lite for IPv6.

Procedure

  Command or Action Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

ipv6 unicast-routing

Example:

Router(config)# ipv6 unicast-routing

Enables the forwarding of IPv6 unicast datagrams.

Step 4

ipv6 cef

Example:

Router(config)# ipv6 cef

Enables Cisco Express Forwarding for IPv6.

Step 5

vrf definition vrf-name

Example:

Router(config)# vrf definition vpn_1

Configures a virtual routing and forwarding (VRF) routing table instance and enter VRF configuration mode.

Step 6

address-family ipv6 unicast

Example:

Router(config-vrf)# address-family ipv6 unicast

Specifies the IPv6 address family, and enters address family configuration mode.

Configuring VRF Lite in SVI Configuration Mode

Perform this task to configure VRF Lite in SVI configuration mode.

Procedure

  Command or Action Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface vlan vlan-number

Example:

Router(config)# interface vlan 17

Enters SVI interface configuration mode. vlan-number is the number associated with the tunnel interface.

Step 4

vrf forwarding name

Example:

Router(config-if)# vrf forwarding vpn_1

Associate a VRF with a peer.

Configuring VRF Lite over GRE Tunnel

Perform this task to configure VRF lite over GRE tunnel. The core network should be under the same VRF as the tunnel.

Procedure

  Command or Action Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface tunnel number

Example:

Router(config)# interface Tunnel 0

Enters tunnel interface configuration mode. number is the number associated with the tunnel interface.

Step 4

vrf forwarding name

Example:

Router(config-if)# vrf forwarding vpn_1

Associate a VRF with a peer.

Step 5

tunnel vrf name

Example:

Router(config-if)# tunnel vrf vpn_1

Associates a VRF instance with a specific tunnel destination.

Adding Static Route to the Tunnel

Perform this task to add a static route to the GRE tunnel.

Procedure

  Command or Action Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

ip route vrf vpn-name ipv4-address subnet-mask tunnel number

Example:

Router(config)# ip route vrf vpn_1 19.19.19.1 255.255.255.0 tunnel 0

Establishes static routes for a Virtual Private Network (VPN) routing and forwarding (VRF) instance.

Note

 

Ensure that VRF enabled prefixes are not present in the global routing table.

Configuring GRE QoS Table Map Support

To configure GRE QoS Table Map support, you need to configure the following:

  • Ingress policy-map: It is used to associated to a GigabitEthernet interface as an in-bound policy.
  • Table Map.
  • Egress policy-map: It is used to associated to a GRE as an outbound policy.

Configuring Service-Policy

Procedure

  Command or Action Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

class-map match-anyclass-map-name

Example:

Router(config)# class-map match-any dscp_class

Creates a class map to be used for matching packets to a specified class and enters QoS class-map configuration mode.

Step 4

match dscp dscp-value

Example:

Router(config-cmap)# match dscp 38

Identifies a specific quality of service (QoS) group value as a match criterion.

Step 5

exit

Example:

Router(config-cmap)# exit

Enters global configuration mode.

Step 6

policy-map policy-map-name

Example:

Router(config)# policy-map policy_dscp

Creates a policy map that can be attached to one or more interfaces to specify a service policy.

Step 7

class class-name

Example:

Router(config-pmap)# class dscp_class

Associates a map class with the policy-map.

Step 8

set qos-group group-id

Example:

Router(config-pmap)# set qos-group 5

Configures a quality of service (QoS) group identifier (ID) that can be used later to classify packets.

Step 9

exit

Example:

Router(config-pmap)# exit

Enters global configuration mode.

Step 10

interface GigabitEthernet number

Example:

Router(config)# interface GigabitEthernet 0/1

Enters gigabitethernet interface configuration mode. number is the number associated with the interface. Here the Marked Traffic is coming from the host.

Step 11

service-policy input policy-map

Example:

Router(config-if)# service-policy input policy_dscp

Attaches the policy map to a gigabitethernet interface as an inbound.

What to do next

Configure a Table-Map

Configuring a Table-Map

Perform this task to configure a table-map.

Before you begin

Before configuring table-map, ensure that there is an ingress policy, and then remark using the table-map.

Procedure

  Command or Action Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

table-map table-map-name

Example:

Router(config)# table-map TABLE3

Configures a mapping table for mapping and converting one packet-marking value to another.

Note

 

The Cisco ASR 901 router supports DSCP to QoS and QoS to DSCP. However, it is not supported directly from DSCP to DSCP and the same is also applicable for precedence values.

Step 4

map from value to value

Example:

Router(config-tablemap)# map from 5 to 7

Maps 'From' value to 'To' value. This step is remarking from qos-group (5) to dscp value (7).

What to do next

Create a policy-map to associate to the GRE tunnel.

Configuring a Policy-Map

Perform this task to configure a policy-map.

Procedure

  Command or Action Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

policy-map policy-map-name

Example:

Router(config)# policy-map POLICY3

Creates a policy map that can be attached to one or more interfaces to specify a service policy.

Step 4

class class-default

Example:

Router(config-pmap)# class class-default

Associate a class-default with policy-map.

Step 5

set dscp qos-grouptable table-map-name

Example:

Router(config-pmap-c)# set dscp qos-group table TABLE3

Marks a packet by setting the QoS group value in the type of service (ToS) byte. This step is associating the table-map to policy-map.

Associating Service Policy to the GRE Tunnel

Perform this task to associate a service policy to the GRE tunnel.

Procedure

  Command or Action Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface tunnel number

Example:

Router(config)# interface Tunnel 0

Enters tunnel interface configuration mode. number is the number associated with the tunnel interface.

Step 4

service-policy output name

Example:

Router(config-if)# service-policy output POLICY3

Associate a policy map to GRE tunnel as an outbound service-policy.

Note

 

To verify the remarking matching counters, configure a policy-map in intermediate router and associate it to the ingress port.

Verifying the GRE Configuration

Use the show commands given in the following examples to verify the GRE configuration.

To display the contents of the tunnel interface, use the show running-config command. 


Router# show running-config interface tunnel 0

Building configuration...

Current configuration : 160 bytes
!
interface Tunnel0
 ip address 10.0.0.1 255.255.255.252
 keepalive 10 3
 tunnel source 1.1.1.1
 tunnel destination 2.2.2.2
 service-policy output policy2
end

To display the usability status of interfaces configured for IP, use the show ip interface command. 


Router# show ip interface brief | include Tunnel

Tunnel2                35.35.35.1      YES NVRAM  up                    up      
Tunnel10               45.45.45.1      YES NVRAM  up                    up

To display the configuration of a tunnel interface, use the show interface tunnel command. 


Router# show interfaces tunnel 0

Tunnel0 is up, line protocol is up
  Hardware is Tunnel
  Internet address is 10.0.0.1/30
  MTU 17916 bytes, BW 100 Kbit/sec, DLY 50000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation TUNNEL, loopback not set
  Keepalive set (10 sec), retries 3
  Tunnel linestate evaluation up
  Tunnel source 1.1.1.1, destination 2.2.2.2
  Tunnel protocol/transport GRE/IP
    Key disabled, sequencing disabled
    Checksumming of packets disabled
  Tunnel TTL 255
  Tunnel transport MTU 1476 bytes
  Tunnel transmit bandwidth 8000 (kbps)
  Tunnel receive bandwidth 8000 (kbps)
  Last input 01:13:28, output 00:00:08, output hang never
  Last clearing of "show interface" counters 01:13:48
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/0 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     15 packets input, 1416 bytes, 0 no buffer
     Received 0 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     442 packets output, 21216 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 unknown protocol drops
     0 output buffer failures, 0 output buffers swapped out

To display the contents of the gigabitethernet interface, use the show running-config command. 


Router# show running-config interface gigabitEthernet 0/11

Building configuration...

Current configuration : 384 bytes
!
interface GigabitEthernet0/11
 no ip address
 negotiation auto
 no qos-config scheduling-mode min-bw-guarantee
 service-policy input policy1
 service instance 100 ethernet
  encapsulation dot1q 100
  rewrite ingress tag pop 1 symmetric
  bridge-domain 100
 !
 service instance 101 ethernet
  encapsulation dot1q 101
  rewrite ingress tag pop 1 symmetric
  bridge-domain 101
 !
end

To display the statistics and the configurations of the input and output policies that are attached to an interface, use the show policy-map interface command. 


Router# show policy-map interface g0/11

 GigabitEthernet0/11

  Service-policy input: policy1

    Class-map: class1 (match-all)
      0 packets, 0 bytes
      5 minute offered rate 0000 bps, drop rate 0000 bps
      Match:  dscp af43 (38)
      QoS Set
        qos-group 5
          Packets marked 0
        No marking statistics available for this class

    Class-map: class_2 (match-all)
      0 packets, 0 bytes
      5 minute offered rate 0000 bps, drop rate 0000 bps
      Match:  dscp af33 (30)
      QoS Set
        qos-group 3
          Packets marked 0
        No marking statistics available for this class

    Class-map: class-default (match-any)
      0 packets, 0 bytes
      5 minute offered rate 0000 bps, drop rate 0000 bps
      Match: any

To display the configuration of a specified table map or all table maps, use the show table-map command. 


Router# show table-map

 Table Map table_1
 from 5 to 7
 default copy

 Table Map new_table
 default copy

 Table Map table3
 from 0 to 7
 from 5 to 1
 default copy

Configuration Example for IPv4 GRE 

Router# show running-configuration

Building configuration...

Current configuration : 3334 bytes
!
!
!
multilink bundle-name authenticated
!
table-map table_1
 map from  5 to 7
 default copy
table-map new_table
 default copy
!
l3-over-l2 flush buffers
asr901-storm-control-bpdu 1000
!
!
!
class-map match-all class_2
 match dscp af33
class-map match-all class1
 match dscp af43
!
policy-map invalid
 class class-default
  set dscp qos-group table table_1
policy-map policy1
 class class1
  set qos-group 5
 class class_2
  set qos-group 3
policy-map policy2
 class class-default
  set dscp qos-group table new_table
!
!
!
interface Tunnel0
 ip address 10.0.0.1 255.255.255.252
 keepalive 10 3
 tunnel source 1.1.1.1
 tunnel destination 2.2.2.2
 service-policy output policy2
!
interface GigabitEthernet0/0
 no ip address
 negotiation auto
!
interface GigabitEthernet0/1
 no ip address
 negotiation auto
!
interface GigabitEthernet0/2
 no ip address
 negotiation auto
 service instance 34 ethernet
  encapsulation dot1q 34
  rewrite ingress tag pop 1 symmetric
  bridge-domain 34
 !
!
!
interface GigabitEthernet0/11
 no ip address
 negotiation auto
 no qos-config scheduling-mode min-bw-guarantee
 service-policy input policy1
 service instance 100 ethernet
  encapsulation dot1q 100
  rewrite ingress tag pop 1 symmetric
  bridge-domain 100
 !
 service instance 101 ethernet
  encapsulation dot1q 101
  rewrite ingress tag pop 1 symmetric
  bridge-domain 101
 !
!
interface FastEthernet0/0
 ip address 7.44.23.31 255.255.0.0
!
interface Vlan1
 no ip address
 shutdown
!
interface Vlan34
 ip address 1.1.1.1 255.255.255.252
!
interface Vlan100
 ip address 192.168.1.1 255.255.255.0
!
interface Vlan101
 ip address 172.16.1.1 255.255.255.0
!
ip default-gateway 7.44.0.1
ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
ip route 2.2.2.0 255.255.255.252 1.1.1.2
ip route 172.16.2.0 255.255.255.0 Tunnel0
ip route 192.168.2.0 255.255.255.0 Tunnel0
!
!
!
!
control-plane
!
environment monitor
!
line con 0
 exec-timeout 0 0
line vty 0 4
 login
!
exception crashinfo buffersize 128
!
!
end

Configuration Example for IPv6 GRE 


Router# show running-configuration

Building configuration...
 
Current configuration : 3398 bytes
!
! Last configuration change at 16:02:49 IST Wed Mar 4 2015
!
version 15.5
service timestamps debug datetime msec localtime show-timezone
service timestamps log datetime msec localtime show-timezone
!
hostname Pura-2035
!
boot-start-marker
boot-end-marker
!
!
no logging console
!
no aaa new-model
clock timezone IST 5 30
ip cef
!
!
!
!
no ip domain lookup
 
ipv6 unicast-routing
ipv6 cef
!
!
mpls label protocol ldp
multilink bundle-name authenticated
l3-over-l2 flush buffers
asr901-storm-control-bpdu 1000
!
!
spanning-tree mode pvst
spanning-tree extend system-id
license udi pid A901-4C-F-D sn CAT1711U0TZ
license boot level AdvancedMetroIPAccess
!
!
lldp run
!
class-map match-any class_1
match dscp 6
class-map match-any class_2
match dscp 7
!
policy-map policy_2
class class_1
class class_2
!
!
!
!
interface Loopback35
ip address 35.1.1.1 255.255.255.255
ip ospf 1 area 0
!
interface Tunnel100
ip address 100.1.1.2 255.255.255.252
ipv6 address 35:35:35::2/64
keepalive 10 3
tunnel source 34.34.34.2
tunnel destination 34.34.34.1
!
interface GigabitEthernet0/0
no ip address
negotiation auto
service instance 34 ethernet
  encapsulation dot1q 34
  rewrite ingress tag pop 1 symmetric
  bridge-domain 34
!
!
interface GigabitEthernet0/1
no ip address
negotiation auto
!
interface GigabitEthernet0/2
no ip address
negotiation auto
!
interface GigabitEthernet0/3
no ip address
negotiation auto
!
interface GigabitEthernet0/4
no ip address
media-type auto-select
negotiation auto
!
interface GigabitEthernet0/5
no ip address
media-type auto-select
negotiation auto
!
interface GigabitEthernet0/6
no ip address
negotiation auto
!
interface GigabitEthernet0/7
no ip address
media-type auto-select
negotiation auto
!
interface GigabitEthernet0/8
no ip address
negotiation auto
qos-config scheduling-mode min-bw-guarantee
!
interface GigabitEthernet0/9
no ip address
negotiation auto
qos-config scheduling-mode min-bw-guarantee
!
interface GigabitEthernet0/10
no ip address
negotiation auto
no qos-config scheduling-mode min-bw-guarantee
service instance 100 ethernet
  encapsulation dot1q 100
  rewrite ingress tag pop 1 symmetric
  bridge-domain 100
!
!
interface GigabitEthernet0/11
no ip address
negotiation auto
no qos-config scheduling-mode min-bw-guarantee
!
interface FastEthernet0/0
ip address 7.44.23.30 255.255.0.0
!
interface Vlan1
no ip address
!
interface Vlan34
ip address 34.34.34.2 255.255.255.252
ip ospf 1 area 0
!
interface Vlan100
no ip address
ipv6 address 2002::1/64
!
router ospf 1
router-id 35.1.1.1
!
ip default-gateway 7.44.0.1
ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
!
ipv6 route 2001::/64 Tunnel100
!
!
!
control-plane
!
environment monitor
!
line con 0
exec-timeout 0 0
line vty 0 4
login
!
exception crashinfo buffersize 128
!
!
end

Additional References

Related Documents

Related Topic Document Title

Cisco ASR 901 Router Commands

Cisco ASR 901 Series Aggregation Services Router Command Reference

Standards and RFCs

Standard/RFC Title

RFC2784

Generic Routing Encapsulation (GRE)

MIBs

MIB MIBs Link

TUNNEL-MIB

To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs

Technical Assistance

Description Link

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.

To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

http://www.cisco.com/support

Feature Information for Generic Routing Encapsulation

The following table lists the features in this module and provides links to specific configuration information.

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http:/​/​www.cisco.com/​go/​cfn . An account on Cisco.com is not required.


Note

The following table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Table 1. Feature Information for Generic Routing Encapsulation

Feature Name

Releases

Feature Information

Generic Routing Encapsulation

15.5(2)S

This feature was introduced on the Cisco ASR 901 Series Routers.