Traffic flapping in regular intervals

[tharakasj]

We are telecom provider. Edge router is Cisco 7604 with SIP 200 cards

Core Router is cisco 12406. We have a MPLS network. router were connected using

STM1 link. Link is terminated by POS interface of those routers. the issue is that every day traffic flapp in regular intervals (15minuts) from 8.35am to 5pm.

please advice is that virus issue or link issue or router issue.

Anyway no errors in links and router interfaces.

In every flapping time, few packets drops and delays go over 1000ms. but normal delay is 2ms when pingging between routers.

Images is attached .

Please help us to resolve this

[Giuseppe Larosa]

Hello Prageeth,

the original state is a wrong configuration as you can read in the document about clocking on POS interfaces.

I would suggest to put clock internal on C7604 side and to leave it a few days.

In order to understand if the C12000 side is faulty or is a fiber problem you need a maintenance time window in which you perform loopback tests ( this is totally intrusive as  stops user traffic) by configuring loopback mode on C7604 side towards line.

The objective of the test should be to verify if the state of interface on C12000 side reach the up/up looped or up/down looped state.

Hope to help

Giuseppe

[tharakasj]

Dear Friend,

Ok. we will set it like that and let you know the status soon.

Thanks

Prageeth

[tharakasj]

Dear Friend,

Still flapping is occaring.this is the ping over this link. regular interval traffic delay and drop can be shows every 15 minut intervals.

Normal delay time = 2s

delay time When issue is happening = more than 1000ms

Reply from 10.13.0.9: bytes=32 time=3ms TTL=251

Reply from 10.13.0.9: bytes=32 time=2ms TTL=251

Reply from 10.13.0.9: bytes=32 time=2ms TTL=251

Reply from 10.13.0.9: bytes=32 time=2ms TTL=251

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Reply from 10.13.0.9: bytes=32 time=2ms TTL=251

Reply from 10.13.0.9: bytes=32 time=2ms TTL=251

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Request timed out.

Reply from 10.13.0.9: bytes=32 time=2ms TTL=252

Reply from 10.13.0.9: bytes=32 time=2ms TTL=251

Reply from 10.13.0.9: bytes=32 time=2ms TTL=251

Reply from 10.13.0.9: bytes=32 time=2ms TTL=251

Reply from 10.13.0.9: bytes=32 time=2ms TTL=251

Reply from 10.13.0.9: bytes=32 time=2ms TTL=251

Reply from 10.13.0.9: bytes=32 time=2ms TTL=251

Please advice

Prageeth

[Giuseppe Larosa]

Hello Prageth,

if you have a free STM-1 port on the C12000 side I would try to move the link to this different port during a maintenance time window.

You can configure the port as the one in use without causing errors before of the maintenance time window.

Hope to help

Giuseppe