file transfer stalls until target is pinged

[p.houlahan]

Hi All,

I have a weird problem that essentially involves the following structure:

I have 3 cisco boxes (A, B, and C) and each has a pc/mac. For simplicitly, assume client 'a' is connected to A, 'b' to B, and client 'c' to C.

A/a/B/b are in one building, C/c are in another. There is a 100Mbps connection between buildings.

The problem is a/b can communicate with each other just fine, but a/c have problems.

Specifically, if a large file  (100MB say) is transferred between a/c it quickly stalls out, but if 'c' is pinged, the connection wakes up again and the transfer completes.

A utility like SCP is being used.

Any ideas as to what could be causing this?

Thanks in advance for any input,

Padraig.

[rparames]

Hello Padraig,

Setup

a--A-----------C--c   ( can you provide one including the Cisco device platform?)

Does the problem occur when file is transferred from a to c or in the other direction ?

When you have to re-establish the connection do you initiate a ping from c to a ?

Question:

-- Is 'a' and 'c' in the same vlan ?

-- If same vlan do all the switches in the path between 'a' and 'c' lean the mac address of 'a' and 'c' when the file transfer stalls ?

-- If 'a' and 'c' are in different VLAN , can you check if there is assymetric routing?

Lastly, did you try performing capture on the end device NIC using wireshark to see if packets do not make it to end clients? We can isolate if the issue is with end client or network

Regards,

Rahul

PS: I am not very active on CSC, please expect a delay in my response.