[Info-vax] Routing when using two interfaces/networks.

[Jan-Erik Soderholm]

VAXman- @SendSpamHere.ORG wrote:
> In article <hiv6ps$fk1$1 at news.albasani.net>, Jan-Erik Soderholm <jan-erik.soderholm at telia.com> writes:
>> Hi.
>> We have some hard-to-identify network problems at
>> a site and I'm now thinking that it might have something
>> to do with how the routing is setup in the VMS system.
>>
>> The VMS system (the "prod" system) has two interfaces :
>>
>> $ tcpip sh inter
>>
>> Interface   IP_Addr         Network mask
>>
>>  LO0        127.0.0.1       255.0.0.0
>>  WE0        193.183.98.2    255.255.255.0
>>  WE1        10.32.137.1     255.255.255.0
>>
>>
>> The 193.183.x.x is the "old" network that will be removed
>> anytime(tm). The 10.32.x.x network is where most of the other
>> stuff (term-servers, PC-clients and so on) are. Note that
>> most other equipment on 10.32.x.x are on other subnets then
>> 10.32.137.x. The only other host on the 10.32.137.x are mainly
>> the other VMS systems. All "user" equipment are on other
>> 10.32.x.x networks.
>>
>> The current routing looks like this :
>>
>> $ tcpip sh route
>>
>>                        DYNAMIC
>>
>> Type           Destination                    Gateway
>>
>> AN    0.0.0.0                         193.183.98.251
>> AN    10.32.137.0/24                  10.32.137.1
>> AH    10.32.137.1                     10.32.137.1
>> AH    127.0.0.1                       127.0.0.1
>> AN    193.183.98.0/24                 193.183.98.2
>> AH    193.183.98.2                    193.183.98.2
>> st
>> $ tcpip sh route/perm
>>
>>                        PERMANENT
>>
>> Type           Destination                    Gateway
>>
>> PN    0.0.0.0                         193.183.98.251
>>
>>
>> The "dev" system has only one interface and looks like this :
>>
>> $ tcpip sho inter
>>
>> Interface   IP_Addr         Network mask
>>
>>  LO0        127.0.0.1       255.0.0.0
>>  WE1        10.32.137.3     255.255.255.0
>>
>> $ tcpip sh rout
>>
>>                              DYNAMIC
>>
>> Type           Destination                   Gateway
>>
>> AN    0.0.0.0                          10.32.137.254
>> AN    10.32.137.0/24                   10.32.137.3
>> AH    10.32.137.3                      10.32.137.3
>> AH    127.0.0.1                        127.0.0.1
>>
>> $ tcpip sh rout/perm
>>
>>                              PERMANENT
>>
>> Type           Destination                   Gateway
>>
>> PN    0.0.0.0                          10.32.137.254
>>
>>
>> The "problems" we are seeing are e.g. :
>>
>> - Troubles ("hangs") when FTP copying from "prod" to "dev".
>> - Intermittent slow access from PC clients.
>>
>> My guess is that the disturbances are due to the fact that all
>> routing goes through the 193.183.98.251 gateway, even between
>> different 10.32.x.x subnets, right ? And that the solution
>> probably would be to simply move the default router from
>> the 193.183.98.251 gateway to the 10.32.137.254 gateway on
>> the system with two networks ?
>>
>> Jan-Erik.
> 
> Shouldn't your 10... network be routed 10.0.0.0/8 such that the internal
> traffic to the other subnets is NOT routed through to the 193.183.98.251
> gateway?
> 

That is my guess also. But actualy route everything (0.0.0.0)
through the 10... gateway (10.32.137.254).

And all traffic is "internal", 193... is just the old network.

Actualy, the 193... net is more "internal" since it mainly have
some older DECservers left at the moment.

Our plan is to get rid of all of the 193... network, but right
*now* there is still some of it left.

Anyway, I'll probably just try to switch the default route (0.0.0.0)
from 193.183.98.251 to 10.32.137.254 and see what happens... :-)

Jan-Erik.