topic Re: Dead gateway detection in Operating System - HP-UX

Dead gateway detection

Singar — Tue, 24 Sep 2002 11:16:05 GMT

Hi,

Not sure whether HPUX 10.X and 11.X supports "Triggered Reselection method (RFC 816) " for dead gateway detection.

In Windows, it is supported and works fine when a default router goes down.

-singar

Re: Dead gateway detection

Joaquin Gil de Vergara — Tue, 24 Sep 2002 11:20:54 GMT

you can configure gated to use rip or ospf instead static routes...

you must connect the 9000 to a routing switch that speaks this routing protocols too...

this work better

Re: Dead gateway detection

Clemens van Everdingen — Tue, 24 Sep 2002 11:23:20 GMT

Hi,

As from hp-ux 11.00 dead gateway detection is used.

C.

Re: Dead gateway detection

Clemens van Everdingen — Tue, 24 Sep 2002 11:24:22 GMT

Hi,

This is to see how it's configured.

Usable commands:

Check the current value:

ndd -get /dev/ip ip_ire_gw_probe

Disable Dead Gateway Detection:

ndd -set /dev/ip ip_ire_gw_probe 0

Enable Dead Gateway Detection:

ndd -set /dev/ip ip_ire_gw_probe 1

nddconf entry example:

TRANSPORT_NAME[0]=ip
NDD_NAME[0]=ip_ire_gw_probe
NDD_VALUE[0]=0

C.

Re: Dead gateway detection

Ravi_8 — Tue, 24 Sep 2002 11:31:40 GMT

Hi,

if the command
# ndd -get /dev/ip ip_ire_gw_probe returns 1
then dead gateway detection is enabled.

This is enabled only in 11.x not in 10.x

Re: Dead gateway detection

U.SivaKumar_2 — Tue, 24 Sep 2002 11:32:13 GMT

Hi,
Yes , HP-UX supports dead gateway detection like windows ( enabled by default ).

But there is a major difference in criteria of
failover to secondary route between HP-UX and
windows.

In windows , the secondary route is selected only when a TCP session times out trying the
primary gateway. ( health checking via TCP )

But in Hp-UX , the secondary route is selected
only when the primary gateway stops responding
to ICMP messages sent by HP-UX server for health checking. ( health checking via ICMP-udp)

regards,
U.SivaKumar

Re: Dead gateway detection

benoit Bruckert — Tue, 24 Sep 2002 11:32:17 GMT

I had few month ago to solve this kind of trouble.
dead gateway detection is working on HP-UX 11. But it 's using the round trip detection.
Consider this case :
define 2 default gateways : 1 for usual use, the other for exception.
All the packet will use the first gateway.
Your 1st gateway is falling :
Packets will go through the second which is what you want.
But when you first gateway goes back, it still use the backup gateway, which isn't what you want ....
In fact it works more like a load sharing than like a standby gateway. It depends of what you want.
For me the solution was to configure rip on the gateways and gated on the HP-UX.
And I agree with you that in Windows the dead gateway detection is working like a backup gateway - and not like load sharing....

hope that help
Benoit

Re: Dead gateway detection

benoit Bruckert — Tue, 24 Sep 2002 11:35:23 GMT

Well,
USika.. explain better than I did what I wanted to say !!!

Re: Dead gateway detection

harry d brown jr — Tue, 24 Sep 2002 11:38:29 GMT

10.x does not but 11.00 and up does.

live free or die
harry