network card

[Narayanan_2]

I have two networks cards, each with it's own IP:
root@mysmpalpha# ifconfig -a
tu0: flags=c63
inet 137.55.76.242 netmask fffffc00 broadcast 137.55.79.255 ipmtu 1500

tu1: flags=c63
inet 137.55.78.242 netmask fffffc00 broadcast 137.55.79.255 ipmtu 1500

I would like to know if this is fault tolerent setup(similar to window2000 where if one card fails the other takes over). If this is not can i set this up on my server(DS20 4.0F)

[Michael Schulte zur Sur · Accepted solution]

Hi,

your setup is not fault tolerant. How to setup netrain you find chapter 2.4 in:
http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/V40F_HTML/APS2SDTE/TITLE.HTM

Michael

[Ralf Puchner]

why should your setup be fault tolerant? You configured 2 network cards in 2 different networks, how should routing works in case one card failed - this is also a problem within Windows?

The only fault tolerant setup with ONE ip address is via netrain. Michael gave you a link in his posting. Within netrain you can configure network adapters to form a single network interface (nr0 etc) failing over in case of a problem.

[Narayanan_2]

tu1 is setup as alias. What does alias means?

[Ralf Puchner]

alias means you configured a second IP adress to an adapter already using an IP.

# ifconfig tu0 alias x.y.z

4.x does not support different IP ranges on the same adapter. This code is within the 5.x pool ("multinet" option for ifconfig).

You *might* have problems with ARP prior to 5.1 depending on your network topology since all requests will have the source address of the primary IP address of the interface,
and not the alias IP address of the correct subnet.

[Michael Schulte zur Sur]

Hi Ralf,

if I am not mistaken, then both network cards are in the same network segement as can be seen by the brodcast address, or am I wrong?

Michael

[Ralf Puchner]

Michael,

both adresses will be forwarded to the same mac address, that is true. But there are some restrictions if using adresses on different subnets. This is not handled properly by older Tru64 versions.

Version 4.0f supports "Latent Support" for Multiple Network Adapters in the same subnet (must be enabled by a kernel value). Older versions routed the traffic always through the first adapter in the subnet and not to all adapters.