Default gateway on HP-UX 11 problem

[David Manson]

We have an A400 running HP-UX 11.00. We have set the default gateway address in the netconf file, and turned off "Dead Gateway Detection" by
# ndd -set /dev/ip ip_ire_gw_probe 0
The problem we are experiencing is that after only about 3 mins following reboot the default gateway definition disappears out of the routing tables.
To get around this problem we have added a manual "route add default (IP address) 1" to the /sbin/init.d/net start-up script.
If anyone has experienced a similar problem or has any suggestions it would be much appreciated.

Thanks,
Dave

[Ravi_8]

Hi, David
even i too facing the same problem in Compaq unix 5.1. we need to add the default gateway after each reboot. even the compaq people failed to solve this prblem, we are living with this problem. In HP if you add default gateway in netconf file, system will recognise this at boot time.if not create a "defaultrouter" file in /etc and add the ip of the gateway in the file

[someone_4]

What is you have more then 1 static route that you have to add? When you reboot all the static routes clear out of the route table. Is there a way to add them somewhere to where they are added on boot time?

richard

[John Waller]

David,

I've never heard of this "Dead Gateway Detection" so have no idea of what it does but perhaps that is your problem. Does it mean that if nobody uses the gateway it removes it ? . Normally I just setup the gateways in the /etc/rc.config.d file as follows.

ROUTE_GATEWAY[0]=xxx.xxx.xxx.xxx
ROUTE_COUNT[0]=1
ROUTE_DESTINATION[0]=default

ROUTE_GATEWAY[1]=nnn.nnn.nnn.nnn
ROUTE_MASK[1]=255.255.255.0
ROUTE_COUNT[1]=1
ROUTE_DESTINATION[1]=123.123.123.0 net

The above sets up a default gateway and also a special route to a dedicated network. I have used this method since earlier releases of HP-UX and have not lost a route yet.

[rick jones · Accepted solution]

If dead gateway detection is indeed disabled (double-check after boot completes), the next possible cuplrit is a running gated, or rdpd (router discovery protocol daemon).

Dead gateway detection is something added to HP-UX 11 to detect "dead" gateways. It does this by pinging the gateway. If the gateway fails to respond to some number of pings, the routing code considers it to be dead and the system will stop using it.

However, many people arbitrarily disable responding to ICMP messages (eg PCMP Echo Request) on their gateways/routers/whatever, and this means that the dead gateway detection code will get a false positive.

For the question about adding multiple static routes, you want to edit the /etc/rc.config.d/netconf file. I'm guessing there is a way to get SAM to do that; if you edit it by hand be careful with your syntax :) Also, make sure there are no directives at the end of the file which might conflict with your changes - SAM hs (had?) the habit of putting things at the end of the file.

[David Manson]

Thanks everyone. The problem was with a running gated.

Cheers,
Dave