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Poor performance over Catalyst L3 switch network

I have a 6509 core and 4506 dist/access layer network for about 600 users. IOS L3 configured on all Supervisors. My RIS (APPLICATION Servers) are connected to the core 6509s. When I load a 600MB image on a new PC that is also attached to the 6509 the build takes 2 to 3 minutes. When imaging a PC on a 4506 conencted via a L3 Gigabit trunk to the 6509 the load takes 35 minutes!!

User Ports are configured at 100MB full. Trunk ports appear to show no mismatch.

Any suggestions on what may be wrong?


Re: Poor performance over Catalyst L3 switch network

You may be experiencing a duplex mismatch between the user ports and the actual PC. Check for errors in the switch port. If the PC is still set to auto-negotiate link speed, you will usually end up with a duplex mismatch which causes significant performance problems. Try setting the switchport to autonegotiate speed and duplex. I am guessing that the NIC in your PC is set to autonegotiate in the BIOS when it boots up. Since there is no OS (making an assumption that RIS is Win2K Remote Installation Services and you are installing the OS) you would have to lock the speed and duplex in for the card so that it is set when the PC boots.

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Re: Poor performance over Catalyst L3 switch network

This turned out to be a configuration problem with the boot server. The boot server was pointing to the wrong default gateway configured with ICMP redirect. This gateway (Cisco 3640) was getting swamped with all the traffic destined for the Catalyst Switch network. The result was that although traffic was getting to the intended destination it was taking too long. Moral: make sure you check all end device IP configuration before debugging the network

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