I found a Cisco 3662 router have so many Large Buffer and Huge Buffer failures, but I just don't known where these packets come from? as you known, Large Buffer match 5024 bytes and Huge Buffer match 18024 bytes.
another queston: we planning to upgrade the DRAM of this router from 64MB to 128MB, if the IOS will automaticlly tunning the size of the buffer itself?
hi Hao, thanks. but I think you URL did not answer my questions.
I compared two copy of "show buffer" information about two 3662 routers, one have 64MB DRAM and another have 128MB. I found their buffers have no different. so I think my second question have answer already.
Cisco's SE ken told me, these big packets maybe come from router's ethernet, that's mean they were come from switch <- Server. because of router's interface only fragment output packets to match their MTU. if the applications make a big packets, they can tranfer it into router. please confirm it for me.
Not sure about that, maybe Cisco SE's deduction is right. I haven't found any good means to judge exactly where the large and huge buffer failures come from. Well, if it's possible to get any hint from the Output Interpreter?
By the way, from the document, I can find there's an explanation regarding 3600 series router's buffer. Cisco 3600 Series Routers use particles. The interface buffers are atomic buffers, called particles, into which the packets are split. When a packet cannot be fast-switched, the router has to reassemble it in one system buffer because the process switching code cannot handle particles. And private particle pools are used by the interfaces and should not be tuned. When no buffer is available in the free list, the router falls back to the public particle pools. Note that public particle pools cannot be tuned.System buffers are used for process switching. On the Cisco 3600, all these buffers are in the I/O memory which is located in DRAM. You can specify the amount of I/O memory using the memory-size iomem command.
I am not sure if the character of 3600 mentioned above will have any effect on the allocation of system buffer.
So i am looking forward to get any suggestions on this topic too. Thanks!
can you hook a sniffer into the switch ? Maybe then you can trace the source of these large packets. What Ken says sounds ok, the router fragments the packets to I think 1544 in order to be able to send them out.
This document gives several answers on frequently asked questions for PFRv3 channel state behavior.
Q1: What are all the channel operational states from a BR (border role) perspective and what are the rules/conditions to be in each st...
The need was to reach an host inside a LAN through a VPN connection managed by the LAN gateway (Cisco 1921).
The LAN gateway performs NAT and there was a dedicate nat rule for the host i wanted to reach through VPN.
I couldn't connect to the hos...
We have 3 identical switches configured by someone else and would like to claim some of the Gigabit ports(G1/G2/G3/G4) for use on servers. When we try to change the wiring and configuration, we run in to connectivity issues. Attached is a des...