AIX MTU
In some situations, Maximum Transmission Unit (MTU) size should not be optimized as high as 9000. Instead, 1500 could be the right and compatible choice for your AIX system.
Let's see current status of MTU on en0 and en1.
[root@primary01 /]# lsattr -El en0 | grep mtu
mtu 9000 Maximum IP Packet Size for This Device True
mtu_bypass on Enable/Disable largesend for virtual Ethernet True
remmtu 576 Maximum IP Packet Size for REMOTE Networks True
[root@primary01 /]# lsattr -El en1 | grep mtu
mtu 9000 Maximum IP Packet Size for This Device True
mtu_bypass on Enable/Disable largesend for virtual Ethernet True
remmtu 576 Maximum IP Packet Size for REMOTE Networks True
We changed both values back to 1500.
[root@primary01 /]# chdev -l en0 -a mtu=1500
en0 changed
[root@primary01 /]# chdev -l en1 -a mtu=1500
en1 changed
Then we check the results.
[root@primary01 /]# lsattr -El en0 | grep mtu
mtu 1500 Maximum IP Packet Size for This Device True
mtu_bypass on Enable/Disable largesend for virtual Ethernet True
remmtu 576 Maximum IP Packet Size for REMOTE Networks True
[root@primary01 /]# lsattr -El en1 | grep mtu
mtu 1500 Maximum IP Packet Size for This Device True
mtu_bypass on Enable/Disable largesend for virtual Ethernet True
remmtu 576 Maximum IP Packet Size for REMOTE Networks True
Very good information.
Thanks for your appreciation.