AIX 5.2 Tcpip

[conwayd]

I changed IP Address via smit tcpip, now I can ping and telent from only ramdom ip segments, Ex. I can Ping from 127.1.1.x seg but not 127.1.2.x seg
I have used the correct values for IP, Gateway, ans Subnet.
My LAN is set to 100 Full Duplex so I configured to card the same.
Any suggestion would be great

Thank you

 

[usige]

First question: Are you really using 127.x.x.x addresses? The 127.0.0.0 network is reserved for the local loopback interface and shouldn't be used on physical devices. Secondly what does your routing table look like? If you can run the following commands and post their output it would be helpful.

ifconfig -a
netstat -nr

 

[conwayd]

Sorry I just used 127.x.x.x as an example,
Here you go,
Thank you

ifconfig -a
en0: flags=4e080863<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST,GROUPRT,64
BIT,PSEG>
inet 10.1.131.24 netmask 0xffffff00 broadcast 10.1.131.255
en1: flags=4e080863<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST,GROUPRT,64
BIT,PSEG>
inet 0.0.0.0 netmask 0x0
et0: flags=4e080863<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST,GROUPRT,64
BIT,PSEG>
inet 10.1.131.24 netmask 0xffffff00 broadcast 10.1.131.255
lo0: flags=e08084b<UP,BROADCAST,LOOPBACK,RUNNING,SIMPLEX,MULTICAST,GROUPRT,64BIT
>
inet 127.0.0.1 netmask 0xff000000 broadcast 127.255.255.255
inet6 ::1/0

netstat -nr
Routing tables
Destination Gateway Flags Refs Use If PMTU Exp Groups

Route Tree for Protocol Family 2 (Internet):
default 10.1.131.24 UGc 1 0 en0 - - =>
default 10.1.131.1 UGc 1 0 en0 - - =>
default 10.21.130.1 UGc 0 0 en1 - - =>
default 10.21.130.74 UGc 0 0 en1 - -
10.1.131/24 10.1.131.24 U 2 141 en0 - -
10.1.131.24 127.0.0.1 UGHS 0 0 lo0 - -
10.1.132.1 10.1.131.1 UGHW 1 2 en0 - -
10.1.133.1 10.21.130.1 UGHW 1 3 en1 - -
10.1.134/24 10.1.134.1 UGc 0 0 en1 - -
10.1.134.1 10.1.134.1 UGHW 2 19 en1 - -
127/8 127.0.0.1 U 4 185 lo0 - -

Route Tree for Protocol Family 24 (Internet v6):
::1 ::1 UH 0 0 lo0 16896 -

 

[Morsing]

Lots of problems here,

You can only have one default routing entry, delete the rest.

en1 has no ip address. I assume it's not needed??

You have several host entries in the routing table which often causes problems. Unless you know what they're for, remove them.

Cheers

Henrik Morsing
Certified AIX 4.3 Systems Administration
& p690 Technical Support

 

[zaxxon]

Hello,

the routes with the &quot;c&quot;-flag are because of &quot;Cloned Routing&quot;. I am not sure what it was really inteded for, but we never needed it on any of our machines and so we always turn it off, to prevent any problems. We had &quot;Cloned Routing&quot; active about 2 years ago on a heavily used machine, and when the machine got more than 256 network connects, every network connection was going to be very very slow and the users had problems to work with the application on that machine.
So we got some information from IBM-support about this problem and we had to put in following lines at &quot;static routes&quot; in the /etc/rc.net:

##### Turning off Cloned-Routing ######

/usr/sbin/no route_expire=1 >>/dev/null 2>&1
/usr/sbin/no -o udp_pmtu_discover=0 >>/dev/null 2>&1
/usr/sbin/no -o tcp_pmtu_discover=0 >>/dev/null 2>&1

##### Cloned-Routing turned off #####

Reboot the machine to have the changes to be affecting your system and do a netstat -rn. You will see that the evil &quot;c&quot;-Flags are gone ;-) Some of these strange default gateways will be gone too, and I hope there will be only 1 left.

After that, let's see if you still have problems to reach some hosts/networks. Maybe it's an idea to talk to the guys, that are giving you the default gateway, if the routes on it are set up, so that it knows the other networks, you want to reach.

 

[aixTim]

The concept of &quot;default&quot; gateway has changed with aix5 - you can have more than one! The => in the routing table was a problem in earlier versions of AIX, indicating that you had multiple default gateways. With AIX5 multiple defaults are allowed, ie 2 interfaces on separate routers, they are used &quot;round robin&quot; by default or by route &quot;cost&quot;. This &quot;feature&quot; gives resiliance but problems will occur if you have a network cul-de-sac. The symptom would be, &quot;can telnet every second time&quot; - first connection get the valid route, second one get a &quot;dead-end&quot; route.

 

[conwayd]

Hey Thanks, You all have been a huge help