IPV6 tunnel between IOS and IOSXR

[Hamza_MX]

Hello ,

We have an IPV6 tunnel which is configured between 2 Cisco router 1900 with the configuration below :

interface Tunnel1
no ip address
ipv6 address 2001:DB8:20:200:1::2/64
tunnel source GigabitEthernet0/1
tunnel mode ipv6ip
tunnel destination 192.168.1.1

the tunnel work fine with the 2 cisco 1900. 

We have changed one of the router with an ASR 9K (IOSXR version 6.0.2) with the below configuration :

interface tunnel-ip200
ipv6 address 2001:db8:10:200:1::2/64
tunnel mode ipv4
tunnel source xxxx
tunnel destination xxxx

Nothing is working .

ANY recommandation ?

[balaji.bandi]

On IOS XR you need to enable IPv6 guess here :

interface tunnel-ip200

ipv6 enable

[Harold Ritter]

Hi @balaji.bandi ,

IPv6 is enabled automatically when you configured an IPv6 address on an interface. "ipv6 enabled" is only needed if you want to enable link local connectivity between two devices.

Regards,

[balaji.bandi]

@Harold Ritter thanks for the input, as per my notes when i was doing lab, i have to issue that to work, so my input., may be i can not remeber may be you right, thank again for the input.

and good catch on this ipv6 address 2001:db8:10:200:1::2/64

[Harold Ritter]

Hi @Hamza_MX ,

The tunnel ipv6 address on the ASR9k is on a different subnet than the one on the ios side, therefore they will not be able to communicate. Try changing the address as follow:

interface tunnel-ip200
ipv6 address 2001:db8:20:200:1::1/64

Regards,

[Hamza_MX]

Hello 

Sorry for the output error but the correct ips are :  2001:db8:10:200:1::2/64 and 2001:db8:10:200:1::1/64 which are on same subnet 

Have tried also 2011::1 and 2011::2 and i got the same problem .

I suspect the software version of the IOS-XR which is 6.0.2 because i cant find command like ## tunnel mode ipv6ip

Best Regards

[Harold Ritter]

Hi @Hamza_MX ,

> I suspect the software version of the IOS-XR which is 6.0.2 because i cant find command like ## tunnel mode ipv6ip

"tunnel mode ipv4" should work just fine. I have it configured on XRv9k in my lab and it works fine against an ios router with configuration similar to yours. 

Can you provide the following output: from the ASR9k:

sh cef ipv6 2001:db8:10:200::/64

Regards

[Hamza_MX]

Hi Harold 

Please find below the output of show cef ipv6 :

RP/0/RSP0/CPU0:ios#sh cef ipv6 2001:db8:10:200::/64
Wed Mar 16 13:44:55.835 UTC
2001:db8:10:200::/64, version 12, attached, connected, internal 0x1000061 0x0 (ptr 0x71eee864) [1], 0x0 (0x71e8aa28), 0x0 (0x0)
Updated Mar 16 13:43:52.274
local adjacency point2point
Prefix Len 64, traffic index 0, precedence n/a, priority 0
via tunnel-ip200, 3 dependencies, weight 0, class 0 [flags 0x8]
path-idx 0 NHID 0x0 [0x717de508 0x0]
local adjacency
RP/0/RSP0/CPU0:ios#

[Harold Ritter]

Hi @Hamza_MX ,

It works just fine with XRv9k and I could not find any specific restriction on the ASR9k platform. 

Can you please share the "show int tunnel-ip200" and "show int tu1" output?

Regards,

[Hamza_MX]

Hello 

I have made a test in the Same ASR9K with a cable between 2 Vrf --and Same issue 

find config below :

interface tunnel-ip223
ipv6 address 2023::1/64
tunnel mode ipv4
tunnel source TenGigE0/2/0/2
tunnel destination 192.168.1.2
!
interface tunnel-ip224
vrf Peering
ipv6 address 2023::2/64
tunnel mode ipv4
tunnel source TenGigE0/2/0/3
tunnel vrf Peering
tunnel destination 192.168.1.1

!!!!

[Georg Pauwen]

Hello,

do the tunnel source interfaces have an IPv6 address ? Post the full running configs of both ASR 9Ks...

[Hamza_MX]

Hello

The tunnel source is an ipv4 routed interface @Georg Pauwen 

I tested the configuration on my virtual lab using XRV and IOS and worked properly like you said @Harold Ritter 

May be the problem is related to the ASR9K , but show cef ipv6 2001:db8:10:200::/64 is showing correct result 

!!!

Best Regards

[Harold Ritter]

Hi @Hamza_MX ,

This is supported on the ASR9k, as mentioned in the following document:

https://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k-r7-3/lxvpn/configuration/guide/b-l3vpn-cg-asr9000-73x/implementing-IP-in-IP-tunnel.html

I ran a quick test in my lab between two asr9k and it works like a charm.

Are the C1900 and asr9k directly connected or is there any other devices in between?

Regards,

[Hamza_MX]

Hi @Harold Ritter 

On my virtual lab it worked also properly .

> Are the C1900 and asr9k directly connected or is there any other devices in between? Yes they are directly connected. 

Source & Destination Tunnel are routed loopback which are pingable.

Regards

[Harold Ritter]

Hi @Hamza_MX ,

Please send the output for the following commands from the ASR9k in a private message if you need further assistance:

show platform

sh cef ipv6 2001:db8:10:200::/64 int

sh adjacency tunnel-ip201 int det

Regards,