problem connecting to DMZ servers

[Burhan Koni]

Hi
I have 4 HP9000 servers all on the same subnet(172.16.0.0), I have problem sometimes in connect to servers in DMZ (212.14.224.0)or any site through the router, the problem cause is not known. the network engineer said the problem may be because multiple network cards on the server having IP's from the same subnet.

your help is highly appreciated
Burhan

[G. Vrijhoeven]

Burhan,

I do not think it is possible to configure mutiple interfaces on the same subnet without APA software. Can it be that you have configured multiple ipadresses on the same interface card?

Gideon

[Elmar P. Kolkman]

I can think of two things:
1) firewall between the DMZ and your other network. For instance, the port you connect to is defined by the service you use, but the port you come from may differ...
2) route settings on the DMZ servers. If your DMZ server has multiple network cards, they need to have good route settings to reach your internal network.

It also depends on what you mean by sometimes. Do you mean that it sometimes works and sometimes not for the same command?

[Burhan Koni]

Gideon,
each server has 3 network cards, the card has only one IP.

[Burhan Koni]

Guys,
sometimes I can connect without any problem, and other times without any change in the settings on the server or the routing on the router, the servers could not reach DMZ

[Elmar P. Kolkman]

If you mean you have the same IP address on all cards, which would be interesting on a DMZ server, it would explain your problem I think...
If you mean one IP per card, I think you need to give more info on subnets, routes, etc.

[G. Vrijhoeven]

Hi,

Can you show me the output of netstat -in of one of the servers?
If it only happens sometimes option 1 of Elmar can be th couse.


Gideon

[Burhan Koni]

here is the output
# netstat -in
Name Mtu Network Address Ipkts Opkts
lan2* 1500 172.16.0.0 172.16.1.25 3 3
lan1* 1500 172.16.0.0 172.16.1.27 192453 38421
lan0 1500 172.16.0.0 172.16.1.26 1536733 267220
lo0 4136 127.0.0.0 127.0.0.1 7253 7253
#

[G. Vrijhoeven]

Burhan,

Could you check if
lan2* 1500 172.16.0.0 172.16.1.25 3 3
lan1* 1500 172.16.0.0 172.16.1.27 192453 38421
are up with ifconfig lan2

I guess both interfaces are down (*).

Gideon

[Burhan Koni]

OK, I disabled these two cards and rebuild the routing table. after that it can connect through the router. but I know the problem will appear again.