02-27-2019 02:46 AM
We are having trouble setting up an IS-IS adjacency across a GRE tunnel, whose endpoints are a couple of IOS-XRv devices.
The GRE tunnel is going across an MPLS cloud.
The tunnel endpoints are reachable. Actually, OSPF is working fine across the GRE tunnel.
Here´s the extract of the configs and I´m ataching the full configs.
XR1
router isis 1
is-type level-2-only
net 49.0000.0000.0011.00
address-family ipv4 unicast
metric-style wide
interface Loopback1
passive
address-family ipv4 unicast
int tunnel-ip 1113
point-to-point
address-family ipv4 unicast
int tunnel-ip 1114
point-to-point
address-family ipv4 unicast
XR3
router isis 1
is-type level-2-only
net 49.0000.0000.0013.00
address-family ipv4 unicast
metric-style wide
interface Loopback1
passive
address-family ipv4 unicast
int tunnel-ip 1213
point-to-point
address-family ipv4 unicast
int tunnel-ip 1113
point-to-point
address-family ipv4 unicast
Thank you in advance.
Alfonso
02-27-2019 03:18 AM - edited 02-27-2019 03:23 AM
It is related to clns mtu.
try to set lsp-mtu under router isis process configuration.
02-27-2019 08:16 AM
02-28-2019 01:44 AM - edited 03-02-2019 09:47 AM
Hi Evgeniy, thanks for the quick reply.
I just tried setting MTU to 1400 and then to 1300, but no luck. Still no adjacency.
RP/0/0/CPU0:XR1#sh isis neighbors
Thu Feb 28 09:43:00.003 UTC
IS-IS 1 neighbors:
System Id Interface SNPA State Holdtime Type IETF-NSF
Everything else looks fine, right?
The GRE tunnel is reachable even with an mtu of 1450 without fragmentation:
RP/0/0/CPU0:XR1#ping 192.168.113.13 size 1450 df-bit
Thu Feb 28 09:35:24.595 UTC
Type escape sequence to abort.
Sending 5, 1450-byte ICMP Echos to 192.168.113.13, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/9/29 ms
Here's the current config of one side (replicated on the other side):
router isis 1
is-type level-2-only
net 49.0000.0000.0011.00
log adjacency changes
lsp-mtu 1300
address-family ipv4 unicast
metric-style wide
mpls ldp auto-config
!
interface Loopback1
passive
address-family ipv4 unicast
!
interface tunnel-ip1113
point-to-point
address-family ipv4 unicast
interface tunnel-ip1114
point-to-point
address-family ipv4 unicast
Thank you.
Alfonso
02-28-2019 08:40 AM
Hi Alfonso,
I have this working perfectly well with XRv 6.1.3. You might want to run some debugs to see what is going on.
Regards,
03-02-2019 09:44 AM - edited 03-02-2019 09:46 AM
Well, I'm doing this with XRv 6.1.2.
Is your IS-IS adjacency going over a GRE tunnel as well?
If so, could you please share your full config?
"debug isis adjacencies" is not showing anything:
RP/0/0/CPU0:XR1#show debug
Sat Mar 2 17:40:47.982 UTC
#### debug flags set from tty 'vty0' ####
clns events flag is ON with value 0
isis adjacencies flag is ON with value 'unfiltered'
Is that an indication of something?
Regards.
Alfonso
03-15-2019 03:21 AM
Apparently it's not MTU related.
Any more ideas?
Anyone?
03-15-2019 04:49 AM
Hello,
on a side note, when I configure the router, the system displays the message below and adjusts the MTU automatically.
Can you post the output of:
show isis interface tunnel-ip1113
from both sides ?
RP/0/0/CPU0:XR2#RP/0/0/CPU0:Mar 15 11:42:04.101 : isis[1010]: %ROUTING-ISIS-4-SNPTOOBIG : L2 SNP size 1492 too big for interface tunnel-ip1113 MTU 1476, trimmed to interface MTU
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: