Contents

Introduction

EIGRP for IPv6

What’s New

Limitations

Supported

Not Supported

Prerequisites, Supported Platforms

Feature Details

Functional Feature Description

EIGRP Features

EIGRP Functional Overview

How It Works

EIGRP Message Flows

Establishing Neighborship

Internal View / ASA CLI

Neighborship: Basic Config and Multi/Unicast

Neighborship: Specify Interface and Router ID

Basic Neighborship

Verify

Check Neighborship State

Hello and Hold Interval Configuration

Passive Interface Configuration

Distribute List for Route Filtering

Redistributing Routes from Other Protocols

EIGRP IPv6 in ASDM

Overview of New Options for EIGRPv6

EIGRPv6 Configuration in Interface

Configuring EIGRPv6 Settings for an Interface

Process Instances and Passive Interfaces

Passive Interfaces Configuration

Router EIGRP and Default Metrics Configuration

Filter Rules (Distribute-List) Configuration

Redistribute Routes Configuration

Neighbor: Unicast Router Mode

Multicast Router Mode

IPv6 EIGRP in CSM

Overview of New Options in CSM for EIGRPv6

Enable EIGRP IPv6 Support

EIGRP IPv6 Setup Tab

EIGRP IPv6 Neighbors Tab

EIGRP IPv6 Redistribution Tab

EIGRP IPv6 Summary Address Tab

EIGRP IPv6 Interfaces Tab

Troubleshooting

Steps to Troubleshoot

Sample Problem

Introduction

This document describes how to configure EIGRP IPV6 on Cisco Adaptive Security Appliance (ASA)

EIGRP for IPv6

• EIGRP for IPv4 is support already available on ASA. There is increasing demand for EIGRP IPv6.

• The configuration for EIGRPv4 and EIGRPv6 are similar, but they can be configured and managed independently.

• Due to differences in protocols, configuration and operation differ slightly.

What’s New

• The earlier releases (prior to ASA 9.20) EIGRP was supported only for IPv4 and from ASA 9.20 onwards,EIGRP would be supported with IPV6

• Support for EIGRP IPv6 with link-local address on ASA only.

Limitations

Supported

• EIGRPv6 is currently supported on ASA only on routed mode, HA, and cluster.

• EIGRPv6 neighborship can be enabled only with link local address.

Not Supported

• Transparent mode

• Multi Context

• Authentication

• On FTD

Prerequisites, Supported Platforms

Minimum Supported Software & Hardware Platforms

Min Supported Manager Version

Managed Devices

Min Supported Managed Device Version Required

Notes

ASA

All ASA platforms

9.20.1

CLI

CSM

All ASA platforms

4.27

CSM GUI

ASDM

All ASA platforms

7.20.1

ASDM GUI

Feature Details

Functional Feature Description

•EIGRP for IPv6 uses the same framework as EIGRP for IPv4.

• EIGRP IPv6 would communicate only with IPv6 peers and advertise only IPv6 routes.

EIGRP IPV4 and EIGRP IPv6 share similar characteristics as well like:

• Neighbour, routing, and topology tables are maintained.

• It uses DUAL stack for fast convergence and loop free network.

The differences are:

• The network command under router-mode is not used for EIGRP IPv6.

• Use "ipv6 router eigrp <AS>" to enable EIGRP IPV6 router process.

• Explicitly configure "ipv6 eigrp <AS>" to enable EIGRP IPv6 on specific interface.

• User configured IPv6 address cannot be used to establish neighborship.

• Authentication is not supported in current release.

EIGRP Features

EIGRP Functional Overview

• EIGRP for IPv6 would be same as EIGRP IPv4

• EIGRP uses the Diffusing Update Algorithm (DUAL) to achieve rapid convergence.

DUAL not only calculates the best routes but also loop free routes.

There are mainly two tables used by DUAL to for calculation of best route. They are neighbor routing table, topology table.

DUAL calculates alternative path based on reported feasible distance.

• The neighbor table keeps track of all directly connected neighbors. Hello packets are used to check that status of neighbor.

• Topology table keeps information on metrics of all routes in the network. Successor and feasible successor keep the best path and alternate path information.

How It Works

- Hello messages are used to discover neighbor before establishing adjacency

- Update messages are exchanged between neighbors to build topology table and routing table.

- Query messages are sent to other EIGRP neighbors for a feasible successor when DUAL is re-computing a route in which the firewall does not have a feasible successor

- Reply messages are sent as the response to an EIGRP Query packet

- Acknowledge messages are used to acknowledge EIGRP Updates, Queries, and Replies

EIGRP Message Flows

- EIGRP IPv6 uses a Hello packet to discover other EIGRP-capable devices on directly attached links and to form neighbor relationships.

- EIGRP IPv6 transmits Hello packets with a source address being the link-local address of the transmitting interface.

- Hello messages are like keep alive messages to keep track of the neighbor status. Default timer of hello message is 5 seconds.

- Upon Hello message exchange, an update message is received and sent. This is used to build the topology table and install the routes in the RIB accordingly.

Establishing Neighborship

Internal View / ASA CLI

Neighborship: Basic Config and Multi/Unicast

- To establish neighborship, router mode config is needed. It is same as for IPv4 except for the config starts with IPv6 keyword.

- It also needs to attach the participating interface to autonomous system.

- Neighborship can be formed in two ways, using either multicast or unicast.

Neighborship: Specify Interface and Router ID

- In addition to router mode configuration, the interface participating in the neighborship needs to be attached to respective autonomous system.

- Make sure to enable IPv6 on the interface.

- Router id is needed for neighborship to form. It would be taken implicitly from the IPv4 interface, or it has to be configured explicitly under router mode, else neighborship would not be formed.

Basic Neighborship

We have simple directly connected topology and configuration for unicast and multicast neighborship

Verify

Check Neighborship State

“show ipv6 eigrp neighbors” is used to check the neighborship state

ciscoasa(config-rtr)# show ipv6 eigrp neighbors

EIGRP-IPv6 Neighbors for AS(50)

H Address              Interface  Hold    Uptime   SRTT  RTO         Q         Seq

(sec)     (ms)              Cnt       Num

1 Link-local address:     m3     12      1w3d      270    1620       0     153 fe80::250:56ff:fe9f:e7e8

0 Link-local address:     m2     12      1w3d      174    1044       0     152 fe80::250:56ff:fe9f:8d83

Hello and Hold Interval Configuration

- Hello interval and Hold interval can be configured using the configurations under interface.

- For non-broadcast multiple access network (NBMA) interfaces, the default value of hello timer is 5 seconds and hold time default value is 15 seconds.

ciscoasa(config-if)# ipv6 hello-interval eigrp 100 ?

interface mode commands/options:

<1-65535>  Seconds between hello transmissions

ciscoasa(config-if)#

ciscoasa(config-if)# ipv6 hold-time eigrp 200 ?

interface mode commands/options:

<1-65535>  Seconds before neighbor is considered down

ciscoasa(config-if)#

Passive Interface Configuration

- In case we do not want an interface to form neighborship, passive-interface config can be used so that Hellos on the interface wiouldnot be sent and not form adjacency.

ciscoasa(config-rtr)# passive-interface ?

ipv6-router mode commands/options:

Current available interface(s):

default  Suppress routing updates on all interfaces

g0       Name of interface GigabitEthernet0/0

mgmt     Name of interface Management0/0

ciscoasa(config-rtr)#

Distribute List for Route Filtering

- Distribute list can be used along with the prefix config to filter routing updates either incoming or outgoing for given interface.

ciscoasa(config-rtr)# distribute-list prefix-list abc ?

ipv6-router mode commands/options:

in   Filter incoming routing updates

out  Filter outgoing routing updates

ciscoasa(config-rtr)#

Redistributing Routes from Other Protocols

- Routes from other routing protocols can be redistributed into EIGRP.

- Use the redistribute command under router.

ciscoasa(config-rtr)# redistribute ?

ipv6-router mode commands/options:

bgp        Border Gateway Protocol (BGP)

connected  Connected Routes

eigrp      Enhanced Interior Gateway Routing Protocol (EIGRP)

isis       ISO IS-IS

ospf       Open Shortest Path First (OSPF)

static     Static Routes

ciscoasa(config-rtr)#

EIGRP IPv6 in ASDM

Overview of New Options for EIGRPv6

- EIGRPv6 support is added as part of ASDM 7.20.1.

- EIGRPv6 configuration added as part of interfaces sub CLI command.

- EIGRPv6 configuration added in router and support router commands.

EIGRPv6 Configuration in Interface

1. Navigate to Configuration > Device Setup > Routing > EIGRPv6

2. Select Interface able to see all the interfaces which are supported

Configuring EIGRPv6 Settings for an Interface

1. Navigate to Configuration > Device Setup > Routing > EIGRPv6 > Interface

2. Select Interface & click Edit

3. Select checkbox(es) to configure process ID, Hello  Interval, Hold Time, Split Horizon, and/or Summary Address

4. After configuring the settings,

5. Click OK

6. Click Send

7. The CLIs appear.

8. Click Send, Cancel, or Save to File

Process Instances and Passive Interfaces

1. Navigate to Configuration > Device Setup > Routing > EIGRPv6 > Set up

2. Able to See Process Instances & Passive Interfaces

3. Under Process Instances -> Enable EIGRPv6 Process

Passive Interfaces Configuration

1. Navigate to Configuration > Device Setup > Routing > EIGRPv6 > Set up

2. Click Passive Interfaces -> Add -> Select Interface

3. Click OK

4. Click Apply

5. The CLI window appears

Router EIGRP and Default Metrics Configuration

1. Device Setup > Routing > EIGRPv6 > Set up

2. Click Process Instances -> Provide Process ID Value

3. Click Advanced button.

4. Provide Router ID, Default Metrics, Stub, and log neighbor values

5. Click Apply

6. The CLI window appears

Filter Rules (Distribute-List) Configuration

1. Navigate to Configuration > Device Setup > Routing > EIGRPv6 > Filter Rules

2. Click Add -> Select Prefix list -> Direction  -> Interface

3. Click OK

4. Click Apply

5. The CLI window appears

Redistribute Routes Configuration

1. Navigate to Configuration > Device Setup > Routing > EIGRPv6 > Redistribution

2. Click Add -> Select protocol

3. Provide Optional metrics

4. Click OK.

5. Click Apply

6. The CLI window appears

Neighbor: Unicast Router Mode

1. Navigate to Configuration > Device Setup > Routing > EIGRPv6 > Static Neighbor

2. Click Add -> Select Interface

3. Provide Neighbor Address

4. Click OK.

5. Click Apply

6. The CLI window appears

Multicast Router Mode

The configuration for Multicast router mode is similar to that for Unicast Router Mode.

1. Navigate to Configuration > Device Setup > Routing > EIGRPv6 > Setup

2. Enable checkbox to enable EIGRPv6 Process

3. Enter value in EIGRPv6 Process input filed.

4. Click Apply

5. Able to see the CLI

IPv6 EIGRP in CSM

Overview of New Options in CSM for EIGRPv6

- EIGRPv6 support is added as part of CSM 4.27.

- EIGRPv6 configuration added as part of Interfaces Sub CLI command.

- EIGRPv6 configuration added in Router and Support Router commands

Enable EIGRP IPv6 Support

Navigation: Platform  >Routing  > EIGRP > IPv6 Family

1. Enable IPv6 by clicking the Enable IPv6 EIGRP checkbox.

2. Provide AS Number between 1 and 65535.

3. Tabs allow for configuring Setup (shown here), Filter Rules, Neighbors, Redistribution, Summary Address, and Interfaces.

EIGRP IPv6 Setup Tab

1. Navigation:  Platform >Routing  > EIGRP >  IPv6 Family > Setup Tab

2. Passive Interface has 3 options

None

Default

Specific Interface

3. “Default”  Suppress routing updates on all interfaces

4. In “Specific Interface”, select interface from Interface selector.

5. Assign values to Default Metrics.

6. Click on OK and Save.

EIGRP IPv6 Filter Rules Tab

1. Navigation: Platform > Routing > EIGRP  > IPv6 Family > Filter Rules Tab

2. Select Eigrp Filter Direction according to Direction (either Inbound or Outbound)

3. Select Interface

4. Enter the IPv6 Prefix-list to filter connections based on an IPv6 prefix-list

EIGRP IPv6 Neighbors Tab

1. Navigation: Platform  > Routing  > EIGRP > IPv6 Family  > Neighbors Tab

2. Enter the Interface and Network in the Add/Edit IPv6 Eigrp Neighbor Page dialog.

EIGRP IPv6 Redistribution Tab

Navigation: Platform > Routing  > EIGRP  > IPv6 Family  > Redistribution Tab

1. Click on the Add button and select Protocol. Based on the Protocol selection, other options get enabled.

2. For BGP and OSPF, ID textbox enabled.

3. If OSPF is enabled, “Optional OSPF Redistribution “ options enabled

4. If ISIS is enabled “ISIS Level” is enabled.

EIGRP IPv6 Summary Address Tab

Navigation: Platform > Routing > EIGRP > IPv6 Family > Summary Address Tab

1. Click on the Add button and select interface from Interface selector

2. In Network, select IPv6 address and Administrative Distance value.

3. Click on OK and Save.

EIGRP IPv6 Interfaces Tab

Navigation: Platform > Routing  > EIGRP >  IPv6 Family > Interfaces Tab

1. Click on Add button and  select interface from Interface selector

2. If wished, change the “Hello Interval” and “Hold Time”

3. Split Horizon is enabled by default.  It can be unchecked.

4. Click on OK and Save.

Troubleshooting

Steps to Troubleshoot

- Check the neighborship state using the show commands.

- Check show ipv6 eigrp topology output to verify the contents of topology table

- Use the show ipv6 eigrp events command, which can give useful info on the major events related to EIGRP.

- Use show eigrp tech-support detailed to check neighborship and topology table timer values.

Show ipv6 eigrp events

“show ipv6 eigrp events” displays important event logging in the systems which are helpful in debugging.

ciscoasa(config-rtr)# show ipv6 eigrp events

Event information for AS 50:

1 18:05:56.203 Metric set: 1001::/64 768

2 18:05:56.203 Route installing: 1001::/64 fe80::250:56ff:fe9f:e7e8

4 18:05:56.203 FC sat rdbmet/succmet: 768 512

5 18:05:56.203 Rcv update dest/nh: 1001::/64 fe80::250:56ff:fe9f:e7e8

6 18:05:56.203 Change queue emptied, entries: 1

7 18:05:56.203 Metric set: 1001::/64 768

8 18:05:56.203 Update reason, delay: new if 4294967295

Show ipv6 eigrp timers

“show ipv6 eigrp timers” shows the current hello timer and the hold timer applied.

- Default timer for hello interval and hold timer is 5 seconds and 15 seconds.

- If NBMA interface with lower bandwidth, the default value for hello timer is 15 seconds; for hold timer,180 seconds

ciscoasa(config-rtr)# show ipv6 eigrp timers

EIGRP-IPv6 Timers for AS(50)

Hello Process

Expiration    Type

|       0 .406  (parent)

|       0 .406  Hello (m2)

Update Process

Expiration    Type

|       11.600  (parent)

|       11.600  (parent)

|       11.600  Peer holding

|       11.930  (parent)

|       11.930  Peer holding

Show ipv6 eigrp topology

“show ipv6 eigrp topology” The topology table consists of all destinations advertised by a neighboring router.

ciscoasa(config-rtr)# show ipv6 eigrp topology

EIGRP-IPv6 Topology Table for AS(50)/ID(172.27.173.103)

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,

r - reply Status, s - sia Status

P 1001::/64, 1 successors, FD is 768, serno 8907

via fe80::250:56ff:fe9f:8d83 (768/512), m2

P 3001::/64, 1 successors, FD is 768, serno 8906

via fe80::250:56ff:fe9f:8d83 (768/512), m2

P 2001::/64, 1 successors, FD is 768, serno 8905

via fe80::250:56ff:fe9f:8d83 (768/512), m2

Show Tech for EIGRP

Show tech can be used for troubleshooting as it would collect useful information including timer parameters, neighborship details, traffic statistics for EIGRP, memory usage counters, and others.

ciscoasa(config-if)# show eigrp tech-support detailed ?

exec mode commands/options:

|  Output modifiers

<cr>

ciscoasa(config-if)#

Sample Problem

Problem Seen with Neighbor Formation

- If problem, seen with neighbor formation

- Check if we have at least an IPv4 address configured if router-id is not explicitly configured under router-mode configuration.

- Make sure to configure router-id under router mode configuration.