Originally posted by: kartii

Hi All,

I'm testing ping command on two servers.

say A-->B and C--->D

A,B,C,D are servers

From A-->B:

ping -c 3 -p ff -s30720
This works fine.

From C-->D:

ping -c 3 -p ff -s30720
This is NOT working and 100% packe loss :(

But if I use 8700 instead of 30720 for packet size '-s', then it works.
Now, Kindly let me know which variable is restricting this packet size '-s' and how to increase it in AIX server??

Thanks in Advance.
#AIX-Forum

Originally posted by: dukessd

How do you know it is not a network restriction instead of an AIX setting?

What does the ethernet adapter and interface attribute settings on all four systems show?

It looks to be a packet size issue so check on each adapter and interface on each system:
lsattr -El enx
lsattr -El entx
Where enx/entx it the adapter/interface, like en0, en1, en2 or ent0, ent1, ent2, Etc.

Look at the mtu packet size, jumbo frames, large send, Etc.

HTH
#AIX-Forum

Originally posted by: kartii

I checked all these values. Everything is same in both the servers :(

Kindly let me know how to restrict/increase the socket size of data transfer using ping command?

for ex

ping -c 3 -p ff -s8700 <ip>

is working but not

ping -c 3 -p ff -s32720 <ip>

Where I need to increase the value for the above command to succeed.?

Thanks
Karti
#AIX-Forum

Originally posted by: nagger

A few questions:

1) Do all the servers have exactly the same AIX level?
Use: oslevel -s

2) Do they all have the same network adapters?
I have no idea if this is the limit but bizarre large ping packets might be an adapter limitation.
This would not appear as a AIX feature.
Use lsconf to list the adapters then: lscfg -v -l ent0

3) Like the previous reply I would also suspect this could be a network switch limitations and so not appear in AIX.
Are all the machines directly connected to the same switch and the switch ports don't have limitations.

4) When I tried this I had to use massive packet sizes to get it to fail like:
ping -c 3 -p ff -s327200 green
0821-076 ping: packet size too large.

You could ask AIX Support for the details of the error message.

5) I have never seen a limit on ping sizes but it could be buried in the "no" command options.
As root user, list them with: no -L
and compare your two machines.

If this is an adapter or switch issue then you will not find the cause from AIX details as its external to the machine.

Hope this helps, Nigel Griffiths
#AIX-Forum

Originally posted by: miod18

Hello Nagger

I have a very rare thing. I have two LPARs over the same physical server, with dual vios configurations included SEA failover.

"LPAr1" can reach default Gateway all the time, but second "LPAR2" can not reach the same default Gateway, just for few moments few minutes and then conection is lost. 

I have installed the server many times and the same thing is still happening. I initially thought it had to do with the Hitachi controller ... (something illogical).
Then I realized that turning off the "LPAR1"  the "LPAR2" could reach the GW. However it was temporary just few minutes and again lost connectivity. =( 

Sorry for the inconvenience, but I do not know what else I can look for. Do you have any idea what I can check?

 

Thanks in advance.

 

#AIX-Forum

Originally posted by: miod18

I have a very rare thing. I have two LPARs over the same physical server, with dual vios configurations included SEA failover.

"LPAr1" can reach default Gateway all the time, but second "LPAR2" can not reach the same default Gateway, just for few moments few minutes and then conection is lost. 

I have installed the server many times and the same thing is still happening. I initially thought it had to do with the Hitachi controller ... (something illogical).
Then I realized that turning off the "LPAR1"  the "LPAR2" could reach the GW. However it was temporary just few minutes and again lost connectivity. =( 

Sorry for the inconvenience, but I do not know what else I can look for. Do you have any idea what I can check?

Thanks in advance.

#AIX-Forum

Originally posted by: nagger

Hi miod18,

That is an odd problem.

If you get some pings working then it is unlikely to be a VIOS setup issue.  Bad VIOS set-ups would result in zero pings.

Assuming you have recent hardware, firmware and VIOS software levels = thus eliminating wacko bugs.

My first suggestions is that this sounds like you have duplicate IP addresses i.e. two servers / VM's trying to use the same IP address.

Power off yours and see if you can get a ping: right now, in 5 minutes and after 15 minutes.

Cheers, Nigel

#AIX-Forum