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This chapter contains these sections:
Today, insertion of service appliances (also referred to as service nodes or service endpoints) such as firewalls, load-balancers, etc are needed to secure and optimize applications within a data center. This section describes the Layer 4-Layer 7 service insertion and redirection features offered on VXLAN EVPN fabrics that provides sophisticated mechanisms to onboard and selectively redirect traffic to these services.
The following guidelines and limitations apply to PBR over VXLAN.
The following platforms support PBR over VXLAN:
Cisco Nexus 9332C and 9364C switches
Cisco Nexus 9300-EX switches
Cisco Nexus 9300-FX/FX2/FX3 switches
Cisco Nexus 9300-GX switches
Cisco Nexus 9504 and 9508 switches with -EX/FX line cards
PBR over VXLAN doesn't support the following features:VTEP ECMP, and the load-share keyword in the set {ip | ipv6} next-hop ip-address command.
When you configure bestpath as-path multipath-relax , BGP installs all the multi-paths for IPv4 as best-path in URIB with least metric available among the paths.
When you configure bestpath as-path multipath-relax , BGP doesn't install all the multi-paths for IPv6 as best-path in U6RIB. It will still have the individual metric available for those paths.
To configure basic PBR, in cases where the advanced (and recommended) ePBR functions are not deployed, see the following sections:
Enable the policy-based redirect feature before you can configure a route policy.
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 2 |
[no] feature pbr Example: |
Enables the policy-based routing feature. |
|
Step 3 |
(Optional) show feature Example: |
(Optional)
Displays enabled and disabled features. |
|
Step 4 |
(Optional) copy running-config startup-config Example: |
(Optional)
Saves this configuration change. |
You can use route maps in policy-based routing to assign routing policies to the inbound interface. Cisco NX-OS routes the packets when it finds a next hop and an interface.
 Note |
The switch has a RACL TCAM region by default for IPv4 traffic. |
Configure the RACL TCAM region (using TCAM carving) before you apply the policy-based routing policy. For instructions, see the “Configuring ACL TCAM Region Sizes” section in the Cisco Nexus 9000 Series NX-OS Security Configuration Guide, Release 9.2(x).
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 2 |
interface type slot/port Example: |
Enters interface configuration mode. |
|
Step 3 |
{ip | ipv6} policy route-map map-name Example: |
Assigns a route map for IPv4 or IPv6 policy-based routing to the interface. |
|
Step 4 |
route-map map-name [permit | deny] [seq] Example: |
Creates a route map or enters route-map configuration mode for an existing route map. Use seq to order the entries in a route map. |
|
Step 5 |
match {ip | ipv6} address access-list-name name [name...] Example: |
Matches an IPv4 or IPv6 address against one or more IPv4 or IPv6 access control lists (ACLs). This command is used for policy-based routing and is ignored by route filtering or redistribution. |
|
Step 6 |
set ip next-hop address1 Example: |
Sets the IPv4 next-hop address for policy-based routing. |
|
Step 7 |
set ipv6 next-hop address1 Example: |
Sets the IPv6 next-hop address for policy-based routing. |
|
Step 8 |
(Optional) set interface null0 Example: |
(Optional)
Sets the interface that is used for routing. Use the null0 interface to drop packets. |
|
Step 9 |
(Optional) copy running-config startup-config Example: |
(Optional)
Saves this configuration change. |
To display the policy-based redirect configuration information, perform one of the following tasks:
|
Command |
Purpose |
|---|---|
|
show [ip | ipv6] policy [name] |
Displays information about an IPv4 or IPv6 policy. |
|
show route-map [name] pbr-statistics |
Displays policy statistics. |
Use the route-map map-name pbr-statistics command to enable policy statistics. Use the clear route-map map-name pbr-statistics command to clear these policy statistics.
Perform the following configuration on all tenant VTEPs, excluding the service VTEP.
feature pbr
ipv6 access-list IPV6_App_group_1
10 permit ipv6 any 2001:10:1:1::0/64
ip access-list IPV4_App_group_1
10 permit ip any 10.1.1.0/24
ipv6 access-list IPV6_App_group_2
10 permit ipv6 any 2001:20:1:1::0/64
ip access-list IPV4_App_group_2
10 permit ip any 20.1.1.0/24
route-map IPV6_PBR_Appgroup1 permit 10
match ipv6 address IPV6_App_group_2
set ipv6 next-hop 2001:100:1:1::20 (next hop is that of the firewall)
route-map IPV4_ PBR_Appgroup1 permit 10
match ip address IPV4_App_group_2
set ip next-hop 10.100.1.20 (next hop is that of the firewall)
route-map IPV6_PBR_Appgroup2 permit 10
match ipv6 address IPV6_App_group1
set ipv6 next-hop 2001:100:1:1::20 (next hop is that of the firewall)
route-map IPV4_ PBR_Appgroup2 permit 10
match ip address IPV4_App_group_1
set ip next-hop 10.100.1.20 (next hop is that of the firewall)
interface Vlan10
! tenant SVI appgroup 1
vrf member appgroup
ip address 10.1.1.1/24
no ip redirect
ipv6 address 2001:10:1:1::1/64
no ipv6 redirects
fabric forwarding mode anycast-gateway
ip policy route-map IPV4_ PBR_Appgroup1
ipv6 policy route-map IPV6_PBR_Appgroup1
interface Vlan20
! tenant SVI appgroup 2
vrf member appgroup
ip address 20.1.1.1/24
no ip redirect
ipv6 address 2001:20:1:1::1/64
no ipv6 redirects
fabric forwarding mode anycast-gateway
ip policy route-map IPV4_ PBR_Appgroup2
ipv6 policy route-map IPV6_PBR_Appgroup2
On the service VTEP, the PBR policy is applied on the tenant VRF SVI. This ensures the traffic post decapsulation will be redirected to firewall.
feature pbr
ipv6 access-list IPV6_App_group_1
10 permit ipv6 any 2001:10:1:1::0/64
ip access-list IPV4_App_group_1
10 permit ip any 10.1.1.0/24
ipv6 access-list IPV6_App_group_2
10 permit ipv6 any 2001:20:1:1::0/64
ip access-list IPV4_App_group_2
10 permit ip any 20.1.1.0/24
route-map IPV6_PBR_Appgroup1 permit 10
match ipv6 address IPV6_App_group_2
set ipv6 next-hop 2001:100:1:1::20 (next hop is that of the firewall)
route-map IPV6_PBR_Appgroup permit 20
match ipv6 address IPV6_App_group1
set ipv6 next-hop 2001:100:1:1::20 (next hop is that of the firewall)
route-map IPV4_ PBR_Appgroup permit 10
match ip address IPV4_App_group_2
set ip next-hop 10.100.1.20 (next hop is that of the firewall)
route-map IPV4_ PBR_Appgroup permit 20
match ip address IPV4_App_group_1
set ip next-hop 10.100.1.20 (next hop is that of the firewall)
interface vlan1000
!L3VNI SVI for Tenant VRF
vrf member appgroup
ip forward
ipv6 forward
ipv6 ipv6 address use-link-local-only
ip policy route-map IPV4_ PBR_Appgroup
ipv6 policy route-map IPV6_PBR_Appgroup
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