Re: MTU problem with simple router?

Linux Advanced Routing and Traffic Control

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Friday 25 October 2002 17:38, Ken Price wrote:
> My colo provider provides IP addresses and expects routing much like a T-1
> data provider.  I get 4-5 "WAN" IP addresses and 32 "PUBLIC ROUTABLE" IP
> addresses.  Their enterprise router expects another router (customer
> provided) to handle this forwarding.  In this role, I currently use a
> RedHat 7.3 box with 2 NICs, simply with IP forwarding enabled.  No special
> rules or shaping.  Straight forward enough, and it's always worked without
> a hitch. Behind this router, I have another RedHat box acting as a NAT
> Firewall which protects my server farm.  Now my problem.  We've recently
> developed an application that makes outgoing requests to other websites and
> returns data. I'm noticing a serious lag in the amount of time it takes for
> this data to return to the server vs. our development environment in the
> office which uses a much slower internet link.
>
> If I test from the production RH7.3 "router", all data is returned
> extremely fast.  If I step back to the NAT firewall, or further back into
> the server farm, I get serious delays.  ICMP does not seem to reflect this
> problem, I'm assuming because of it's small packet size.  Could MTU size be
> an issue here?  All of my firewalls and routers use the default 1500 MTU
> size and the network is all 100Mbps up to the OC-48 internet backbone.  Am
> I missing some router configuration?  I've tried adjusting the MTU size on
> the router with no change in results.
>
> Any suggestions on where to go with this?
If I have a tcp delay, I always check the dns config.  In many cases, there is 
no reverse dns lookup of the ip-address so the other hosts waits for the 
dns-timeout before allowing the connection.  So, has your ip-address a 
reverse dns entry?

Stef

-- 

stef.coene@docum.org
 "Using Linux as bandwidth manager"
     http://www.docum.org/
     #lartc @ irc.oftc.net

_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/


[Index of Archives]     [LARTC Home Page]     [Netfilter]     [Netfilter Development]     [Network Development]     [Bugtraq]     [GCC Help]     [Yosemite News]     [Linux Kernel]     [Fedora Users]
  Powered by Linux