Network speed problem

[TonyGroves]

I'm running a small local network with a DSL modem which all machines, Linux (Suse 9) server and Windows PC's, use as their default gateway. Problem is, whenever there is a problem with the DSL modem, if it's disconnected or otherwise down, then local network traffic slows considerably. It's particularly noticeable in database (MySQL/Linux) queries; what normally takes 0.1 sec slows to 10 seconds. Then when the DSL connection gets fixed, everything speeds up again.

Can anybody tell me are there any configuration settings on the Linux server which need to be tweaked in order to fix this?

In case it's relevant, /etc/sysconfig/network/ifcfg-eth-id-[macaddress] contains:
[tt]
BOOTPROTO='static'
BROADCAST='192.168.1.255'
IPADDR='192.168.1.15'
MTU=''
NETMASK='255.255.255.0'
NETWORK='192.168.1.0'
REMOTE_IPADDR=''
STARTMODE='onboot'
UNIQUE='pfEI.LBVHcr87V51'
_nm_name='bus-pci-0000:07:03.0'
[/tt]
And /etc/sysconfig/network/routes contains:
[tt]
default 192.168.1.254 - -
[/tt]

Thanks a lot.

 

[thedaver]

Sounds like your routing is timing out or something.

Would you please post the results of "route -n" with DSL working and potentially again without it?

D.E.R. Management - IT Project Management Consulting

http://www.dermanagement.com/

 

[JorGeVaL]

Is your Linux a DNS client ?

I mean there are lines in your /etc/resolv.conf ?

If so, try this ...

Put commentes in your resolv.conf file when your DSL is down and take a look how it works ...


I hope this can help !

 

[TonyGroves]

thedaver:

"route -n" gives:
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 192.168.1.254 0.0.0.0 UG 0 0 0 eth0

I don't know where the 169.254.0.0 bit came from, I didn't put it in, at least not when I was sober. Does it mean anything? The local network uses only 192.168.1.* and the DSL modem is 192.168.1.254 .

JorGeVal
I'll have a chance to play around with the system all I want at the weekend, so I'll try your suggestion then.


Thanks!

 

[thedaver]

169.254.0.0 is a sort of null, non-routable network. It's automagically added and doesn't impact anything.

I'm guessing that the DNS matter may need some cleaning up... guessing.

D.E.R. Management - IT Project Management Consulting

http://www.dermanagement.com/

 

[TonyGroves]

I should have posted /etc/resolv.conf; here it is:
[tt]
domain dfs
nameserver 159.134.237.6
nameserver 159.134.248.17
[/tt]
Though I can't see how DNS would come into it; we're only talking local network access, using static internal addresses. Database access certainly doesn't use it. The only DNS-using programs that I can think of are the mail server (still on a Windows machine), virus-database updater, and web browsers.

 

[danomac]

I use a linux PC as my router and firewall, and I had the problem you are describing.

I fixed it by adding all my PCs to the routers /etc/hosts file and changing the DNS nameserver to point to the router's IP.

Fixed my problem in a hurry.

 

[danomac]

I should mention that my router is set up to contact external DNS if needed (it's a Smoothwall firewall.)