Interface card loses config on reboot

[ntruby]

I have a 2nd interface card in my server which needs to be set up thus:

ce1: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 3
inet 10.248.3.73 netmask fffffff8 broadcast 10.248.3.79
ether 0:3:ba:4d:dc:8c

No problem to set up with the relevant ifconfig commands.

However, after reboot it looks like this:

ce1: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 3
inet 10.248.3.73 netmask ff000000 broadcast 10.255.255.255
ether 0:3:ba:4d:dc:8c

and I have to change it manually. How can I configure Solaris to preserve
my netmask and broadcast settings?

/etc/netmasks lloks like this:

3.0.0.0 255.0.0.0
10.248.3.0 255.255.255.248

Thanks
Neil

 

[Annihilannic]

Are you sure that's the correct netmask you are using? Because the first 29 bits of the IP address are significant, that netmask actually puts that IP address on a different network (10.248.3.72, not 10.248.3.0), which is the reason why it's not using that line in /etc/netmasks to configure that interface.

If your network should include all IP addresses in the range 10.248.3.0 - 10.248.3.255 then the netmask should be 255.255.255.0. The netmask you are using only includes 10.248.3.0 - 10.248.3.3 (only four IP addresses!).

A logical bitwise AND between any IP address on a network and the netmask should result in the network address, e.g.

[tt]010.248.003.073 = 00001010.11111000.00000011.01001001
AND
255.255.255.000 = 11111111.11111111.11111111.00000000
=
010.248.003.000 = 00001010.11111000.00000011.00000000[/tt]

I hope I'm making sense.


Annihilannic.

 

[ntruby]

Yes, you're spot on.

10.248.3.72 255.255.255.248
fixed it.

Thank you.