NDD - Network Tuning

[Ong Chin Soon]

Hi all,

Would like to ask you all whether the ndd available in HPUX 10.20 cause I couldn't find it in 10.20 but I can find it in HPUX 11.00 onwards. Do I need to get ndd install in 10.20 or 10.20 doesn't need ndd at all? And in 11.11i, where can I see the ip_ire_gw_probe status in GUI? FYI,I couldn't see this parameter in the tunable parameter when I open SAM.

Thanks!

Rgds,
Chin Soon

[Jerome Henry]

Hi,

AFA I know, ndd appears in 11.00 In 10.20, use nettune.

ip_ire_gw are accessible in shell, trhough ndd. Here's a short description from HP :

Turns the Dead Gateway Detection on and off.

IP periodically tests if the gateways are available. It not only probes the
active one, but also the "dead" gateways in case the came back to live in the
meantime. The default for this value is "1", so we probe the gateways.

You could see which value is set by executing:

ndd -get /dev/ip ip_ire_gw_probe

This results in "1" probing or "0" not probing.

To see all gateways you could use ip_ire_status

ndd -get /dev/ip ip_ire_status | grep -e IRE_GATEWAY -e flag

This results in a list of all gateways, the flags will indicate a dead gateway.
Another option ip_ire_gw_probe_interval is available which changes the
frequency in which such probes will be performed.

Why would this be used?

The gateway probes are ICMP packets which await a proper reply.

In cases where e.g. a firewall is used it could be wanted to turn off ICMP, so
nobody could ping the firewall but still it works for the desired protocols.
So turning it off would not compromise the work, because we would never send an
ICMP packet to test the machine. On the other hand we would only know if a
gateway is not operational if we try to use it. This results in long timeouts
during the detection.

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


You can move this question to the HP UX forum if you need more details.

hth

J

[Ong Chin Soon]

Thanks for the informative explaination!

Rgds,
Chin Soon

[PW HP-UX Support Team]

Looks good I believe.

# ndd -get /dev/ip ip_ire_status | grep -e IRE_GATEWAY -e flag
IRE rfq stq addr mask src gateway mxfrg rtt ref type flag
e00000049936c688 0000000000000000 0000000000000000 000.000.000.000 00000000 172.021.062.022 172.021.062.001 01500 00000 000 IRE_GATEWAY