topic Re: Problem with asymmetry in General Topics

Problem with asymmetry

Luciano_Cirino — Mon, 31 Jul 2023 12:20:54 GMT

Good morning everyone,

We are facing an issue with a specific access. When trying to access it, the packet that should exit through the eth8.7 interface, one of the providers we have, is going out through another interface that is not configured.

Problem with asymmetry? Has anyone experienced this before?

Below is an image with the packet capture details.

Re: Problem with asymmetry

Chris_Atkinson — Mon, 31 Jul 2023 12:24:36 GMT

More details are likely required about your configuration, things like NAT and ISP redundancy config?

What does your routing table show as the correct egress path for the destination?

Re: Problem with asymmetry

the_rock — Mon, 31 Jul 2023 12:51:55 GMT

Make sure topology is correct and routes are also indeed right. Run ip r g command, ie ip r g 8.8.8.8

Andy

Re: Problem with asymmetry

the_rock — Mon, 31 Jul 2023 13:02:20 GMT

Also, Im little confused by your statement "...is going out through another interface that is not configured"

How is that even possible?

Andy

Re: Problem with asymmetry

G_W_Albrecht — Mon, 31 Jul 2023 13:39:37 GMT

I would involve CP TAC asap to get this fixed...

Re: Problem with asymmetry

Luciano_Cirino — Mon, 31 Jul 2023 18:00:29 GMT

I'm sorry for the lack of details in the previous explanation.

The packet enters through the interface eth8.7 (link A), goes through the inspection and NAT flow correctly, and then it is returned through eth8.8 (link B).

Re: Problem with asymmetry

Luciano_Cirino — Mon, 31 Jul 2023 18:00:58 GMT

We would like to inform you that we are already in contact with the TAC. Thank you.

Re: Problem with asymmetry

the_rock — Mon, 31 Jul 2023 18:16:42 GMT

Question...is this brand new issue or just started recently? Any changes made?

Andy

Re: Problem with asymmetry

the_rock — Mon, 31 Jul 2023 19:04:31 GMT

What was done with TAC so far?

Andy

Re: Problem with asymmetry

Chris_Atkinson — Mon, 31 Jul 2023 23:21:23 GMT

Can you please show the routing table output for this destination also is there any PBR configured that would match this traffic?

Re: Problem with asymmetry

the_rock — Tue, 01 Aug 2023 00:56:39 GMT

If you could send us below from expert mode, would help, for sure.

route

netstat -nr

clish -c "show route all"

Andy