[Users] vps from different Hardware Nodes can't access each others

[Marc Olive]

On Thursday 31 March 2011 19:22:47 John Spanos wrote:
> Hello ppl

Hello,

> I am new in mailing list but i face a strange situation and i need your
> help to fix it... let me explain
> 
> i have two hardware nodes
> 
> HN1 --> OS:CentOS --> ip_address:192.168.1.1/24
> HN2 --> OS:CentOS --> ip_address:192.168.1.2/24
> 
> i have four vps on each Hardware Node
> 
> vps01_hn1 --> running_on: HN1 --> OS:Debian --> ip_address:192.168.1.100/24
> vps02_hn1 --> running_on: HN1 --> OS:Debian --> ip_address:192.168.1.101/24
> vps03_hn1 --> running_on: HN1 --> OS:Debian --> ip_address:192.168.2.100/24
> vps04_hn1 --> running_on: HN1 --> OS:Debian --> ip_address:192.168.2.101/24
> 
> vps01_hn2 --> running_on: HN2 --> OS:Debian --> ip_address:192.168.1.102/24
> vps02_hn2 --> running_on: HN2 --> OS:Debian --> ip_address:192.168.1.103/24
> vps03_hn2 --> running_on: HN2 --> OS:Debian --> ip_address:192.168.2.102/24
> vps04_hn2 --> running_on: HN2 --> OS:Debian --> ip_address:192.168.2.103/24
> 
> 
> so here is my situation
> 
> when i try to ping or trace from vps01_hn1 to any other vps i am taking a
> normal response when i try to ping or trace from vps03_hn1 to any vps on
> HN1 i get a response but from HN2 i get response only from vps01_hn2 and
> vps02_hn2. the same situation from HN2 vps, vps01_hn2 and vps02_hn2 can
> ping everyone but vps03_hn2 and vps04_hn2 can't ping vps vps03_hn1 and
> vps04_hn1.
> 
> I don't have any iptables.
> any ideas??

You have mixed (sub)nets on each HN, 192.168.1.x and 192.168.2.x. How did you 
routed between subnets/hosts?
Also, if you randomly mix subnets IPs, like 192.168.2.100 on HN1 and 
192.168.2.102 on HN2 then routing tables will be a bit hard, you will need a 
route for every node instead having one route for every net.

I don't know your needs, but splitting subnets in a different way will be 
easier to manage, for example 192.168.1.x for HNs, 192.168.2.x for VPx_HN1 and 
192.168.3.x for VPx_HN2. This way you can route whole subnets to his HN-
gateway, instead of routing individual VPs as you will have to do with the 
configuration you have now.

You should read some docs about routing and net-splitting.

Regards,

-- 

Marc Olivé
Blau Advisors

marc.olive at blauadvisors.com

C/ Molí de Guasch, 10 baixos 1a,
43440 L’Espluga de Francolí (Tarragona)
Tel. +34 977 870 702
Tel i Fax. + 34 977 870 507

www.blauadvisors.com