corrupted MAC on input errror with ssh ...

[K.C. Chan]

Remote server which I am loging into and do an ls on dir which contains may files, I am getting this message:
corrupted MAC on input, and my ssh connection is drop. This happens often enough but not conistence. The version of ssh:
openssh-server-3.1p1-10
openssh-clients-3.1p1-10

The version of ssh on server which I am loging in from:
openssh-3.5p1-11
openssh-server-3.5p1-11
openssh-clients-3.5p1-11

Any idea?

[K.C. Chan]

other variation of the error:
Disconnecting: Bad packet length 225036344

[Gopi Sekar]

Few reasons why it could happen:

* Network issue: too much congestion, too many packet drops, link problem, swithc/hub problem

* Ethernet card problem: Reason could be faulty NIC on either server/client (if other machines are connecting with server without any problem then the NIC card problem may be with client). Try connecting through another NIC

* Which version of linux you are using ? may be this is already known issue with that NIC and the kernel you are trying to use. Try doing google otherwise simply update the system with latest kernel (if possible)

* I believe the latest version of openssh 4.1(I have this in my FC4), try that.

Regards,
Gopi

[K.C. Chan]

I am using rh7.3, with kernel 2.4.26 (custom roll up). Similar box at different located at different ISP does not experience this. The client varies from redhat7.x,8,9 and fc3. How would I determined if it's a bad switch or hub or router? What tools can I used to see if packets are being drop?

As far as updating openssh to 4.1? I am not sure how that will work with the dependecies on it? I will give that a try as well.

Thanks.

[Gopi Sekar]

check the output of '/sbin/ifconfig' it should give the list of error packets and dropped packets. typical values to be checked are:

RX packets:470 errors:0 dropped:0 overruns:0 frame:0
TX packets:2482 errors:0 dropped:0 overruns:0 carrier:0

errors and dropped counter should be zero in your case.

Hope this helps,
Gopi

[K.C. Chan]

Both are zero. Any other idea?

[Ermin Borovac]

I would search ssh bug database to see if you can spot anything similar to your error. In particular have a look at these.

http://bugzilla.mindrot.org/show_bug.cgi?id=510
http://bugzilla.mindrot.org/show_bug.cgi?id=845

[Raj D.]

Hi Chan ,

Try doing it via telnet , and check if you are getting the same , "corrupted MAC on input, " error. Seems its not a problem with SSH , but could be a network related problem. Pls also provide some more details .


Cheers ,
RajD.

[K.C. Chan]

Sorry,Can't test it with telnet. Policy for that is not supported. However I was able to test from outside line. I tested remote ssh access and a long list of ls from my comcast line and did NOT recieve any error where as ssh test from work, failed with "Corrupted MAC on input". However I did the same test with a different remote ISP from my comcast and my office, both test succeeded repeatedly. The only thing which has changed on the remote ISP which I have been having problem with is that they changed wireless broadand equipment (Trango wireless Broadband). According to the tech I am working with, they used to have a different brand. It's hard to convinced them that it's most hilghly likely it's this piece of hardware when the test from our site to their fail, where as from a comcast like to their pass. Any idea or insight into this?