Hello All,
I have a query , we have enabled ip route cache flow on the main ATM IMA interface and we have few subinterfaces configured in it.While looking at the output of ip cache flow I see the source IP add & source interfaces to be different i.e. in the below example 172.18.96.0/22 is a subnet which resides behind AT0/IMA0.75 but I see this subnet as a source / destination IP through a different sub-interfaces.As per the network setup there is no other link for the other sub-interfaces to reach the mentioned subnet.
below is one sample output , we see lot of traffic as highlighted below
AT0/IMA0.776 172.18.96.115 Gi0/0.1 172.18.9.64 06 047D 0882 1 - In this example the mentioned IP should not reflect the source interface as Ima.776 rather it should b only IMA.75 as below.
AT0/IMA0.75 172.18.96.115 Gi0/0.1 172.18.9.64 06 047D 0887 1 - this is right information
AT0/IMA0.779 172.18.11.15 AT0/IMA0.75 172.18.96.186 06 0CF6 0050 1 - this is right inforamtion
configurations
interface ATM0/IMA0
no ip address
ip route-cache flow
logging event subif-link-status
load-interval 30
ima clock-mode common 0
ima differential-delay-maximum 150
atm vc-per-vp 1024
no atm ilmi-keepalive
end
we have these many subinterfaces.ATM0/IMA0.75 is the connection to hub site and the rest are the spoke sites connecting to this router lastly this router is the only transit to reach the hub router.
ATM0/IMA0
ATM0/IMA0.75
ATM0/IMA0.775
ATM0/IMA0.776
ATM0/IMA0.777
ATM0/IMA0.779
No routing issues as the route table looks completly good.
And today I disbaled WAAS ,removed WCCP redirect statement and the traffic flow was normal , would like to know why we see this kind of traffic flow ? Moreover we have seen this kind of traffic flow in different routers as well the common thing on all these routers are
1. Common physical link binded with multiple sub-interfaces
2. WCCP enabled
3. IOS 12.4 25c
Let me know if anyother information is required ..
