Hi All, I've deployed MPLS across parts of our core network and everything appears to be working fine. I've also got MPLS VPN's going which is the main reason for us rolling out MPLs in the first place. However, I've run into a problem with netflow on one of the PE routers that affects normal IP flows when mpls is enabled on the interface. The PE router having this problems is a cisco 7206VXR (NPE-G1) running IOS Version 12.3(22). Other PE routers are not showing this problem but they are 7301's running a different IOS. What I'm finding is that when I enable "tag-switching ip" on interface Gi0/2 which forms part of our MPLS core (as seen below), the netflows for normal IP traffic isn't as it should be. Doing a "show ip cache flow" on the PE router only shows a few flows going through for normal IP traffic and we'd expect more IP cache flows to be going through because lots of customers hang off this PE router. When we remove the "tag-switching ip" from the interface, flows are back to normal. interface GigabitEthernet0/2 mtu 1500 ip address 203.10.110.x 255.255.255.224 ip route-cache flow load-interval 30 duplex full speed 1000 media-type rj45 no negotiation auto tag-switching mtu 1508 tag-switching ip no clns route-cache We are also seeing this in the file size on the netflow collector. After enabling mpls on interface Gi0/2 above on July 29th, you can see that from that time on the file size of flows being collected at 12pm is considerable less than what we would expect. > ls -la *12-2.bz2 -rw-r--r-- 1 root wheel 29224597 Jul 21 12:59 Netstat_2008072112-2.bz2 -rw-r--r-- 1 root wheel 30218681 Jul 22 12:59 Netstat_2008072212-2.bz2 -rw-r--r-- 1 root wheel 28635436 Jul 23 12:59 Netstat_2008072312-2.bz2 -rw-r--r-- 1 root wheel 26987099 Jul 24 12:59 Netstat_2008072412-2.bz2 -rw-r--r-- 1 root wheel 26003303 Jul 25 12:59 Netstat_2008072512-2.bz2 -rw-r--r-- 1 root wheel 4427493 Jul 26 12:59 Netstat_2008072612-2.bz2 -rw-r--r-- 1 root wheel 4758483 Jul 27 12:59 Netstat_2008072712-2.bz2 -rw-r--r-- 1 root wheel 28679702 Jul 28 12:59 Netstat_2008072812-2.bz2 -rw-r--r-- 1 root wheel 222144 Jul 29 12:59 Netstat_2008072912-2.bz2 -rw-r--r-- 1 root wheel 154352 Jul 30 12:59 Netstat_2008073012-2.bz2 -rw-r--r-- 1 root wheel 315422 Jul 31 12:59 Netstat_2008073112-2.bz2 -rw-r--r-- 1 root wheel 388378 Aug 1 12:59 Netstat_2008080112-2.bz2 -rw-r--r-- 1 root wheel 145880 Aug 2 12:59 Netstat_2008080212-2.bz2 -rw-r--r-- 1 root wheel 171154 Aug 3 12:59 Netstat_2008080312-2.bz2 -rw-r--r-- 1 root wheel 410493 Aug 4 12:59 Netstat_2008080412-2.bz2 -rw-r--r-- 1 root wheel 326936 Aug 5 12:59 Netstat_2008080512-2.bz2
Any ideas as to why enabling mpls would be affecting normal IP cache flows? I can only suspect that it's some IOS bug with the IOS we're running . Thanks. Andy This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. Please notify the sender immediately by email if you have received this email by mistake and delete this email from your system. Please note that any views or opinions presented in this email are solely those of the author and do not necessarily represent those of the organisation. Finally, the recipient should check this email and any attachments for the presence of viruses. The organisation accepts no liability for any damage caused by any virus transmitted by this email. _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
