We just deployed a new Internet router that is running a multi-homed BGP setup. Our company provides ICMP and SNMP performance monitoring, mostly via VPN connections.
What we are seeing is a very high rate of transmit discards. I believe these are the result of packet bursts from our monitoring servers. We are using QoS to tag our VPN and monitoring traffic and give it 1 Mbps priority. I have also tuned the buffers to eliminate buffer misses. However, the router is still discarding packets at a very high rate (12,000 per hour). This is causing quite a lot of timeouts for our monitoring systems and affects our reporting accuracy.
Does anyone have any suggestions on how to eliminate these discards. So far I haven't come up with a solution and Cisco TAC hasn't found one for me yet either.
Attached is a copy of the router config (with most of the Ip info cleared out). I'm also attaching a graph showing the discard rates. Again everything we've tried so far has been ineffective. I did force a failover to the AT&T T1 by shutting down the IMA group - that cut the discards in half, but we obviously can't run on our failover link full time.