Re: Slow browsing with cable modem

From: P Gentry (rdgentry1_at_cablelynx.com)
Date: 04/24/04 

Date: 23 Apr 2004 15:13:51 -0700

"Stephen Zilliox" <szilliox@charter.net> wrote in message news:<108hvmqm1lerqbf@corp.supernews.com>...
> Below is the output of : cat /var/lib/dhcp/dhclient-eth0.leases. Of
> interest to me is the "fixed address 68.113.7.247"---this address appears

This _is_ your assigned IP address when in Linux -- normal. See
below.

> nowhere in my windows XP network parameters listing, but has shown up in
> linux in the "network" file as "GATEWAY=68.113.7.247". When this line

Your IP address cannot be the GW router used to connect to other net
segments -- this would indicate _serious_ config problems.

> existed my linux browsers would not access other sites at all, just going
> into the perpetual "waiting for" mode. When I changed the address to
> 66.189.180.1---the default gateway listed under windows XP---then I could

Sheer luck(?) that the GW still had arp entries for your MAC from your
Windows use. The slowness was re-adjusting to the new IP of your
Linux box. When Win is used again, the poor GW is really going to be
confused.

> access some websites as described before with Konqueror and Epiphany
> although very slowly. Mozilla, however, remained in the "waiting for" mode.
> The routers address is one I haven't seen before. All the other addresses in
> the file below are present in windows XP also. Very bizarre. Does this file

According to earlier posts your Win IP is placed on an entirely
different sub-net from your Linux IP -- IP Address=66.189.180.71 for
Win and 68.113.7.247 for Linux. Compare your ifconfig output to your
ifcfg-eth0 file listing in your first post. Big problem here! Or
just a typo, which would be OK and understandable if you're not
cut-n-pasting.

> give any further clues as to what might be going on? I have a feeling that
> the "fixed address" value has something to do with my problem as well as the
> difference between Mozilla and the other two browsers. Thanks alot for
> your assistance. Do you have any further suggestions?
>
> root@stevescomputer network-scripts]# cat /var/lib/dhcp/dhclient-eth0.leases
>
> lease {
> interface "eth0";
> fixed-address 68.113.7.247;
Which is it -- 66.189.180.71 or 68.113.7.247 at ifconfig?

> option subnet-mask 255.255.254.0;
> option time-offset -21600;
> option dhcp-lease-time 172800;
> option routers 68.113.6.1;
> option dhcp-message-type 5;
> option dhcp-server-identifier 192.168.4.27;
> option domain-name-servers
> 66.189.219.29,66.189.219.30,66.169.254.30,66.169.25 4.29;
> option broadcast-address 255.255.255.255;
> renew 5 2004/4/23 22:07:13;
> rebind 6 2004/4/24 21:47:17;
> expire 0 2004/4/25 03:47:17;
> }
This is the previous accepted lease -- used as a backup if lease
request fails.

>
> lease {
> interface "eth0";
> fixed-address 68.113.7.247;
See, 68.113.7.247 _is_ the IP for your Linux interface. This is quite
common on dual boot machines because Win and Linux use different
client-ids when requesting a lease. J.M. is newly familiar with Win
vs. Linux client-ids re: Verizon ;-)

> option subnet-mask 255.255.254.0;
> option time-offset -21600;
> option routers 68.113.6.1;
This is your GW when using Linux. Should be able to ping this almost
as fast as localhost. It _must_ be on the same subnet as you.

> option dhcp-lease-time 172342;
> option dhcp-message-type 5;
> option domain-name-servers
> 66.189.219.29,66.189.219.30,66.169.254.30,66.169.25 4.29;
These are your DNS servers where all name lookups will be sent. They
should also appear in resolv.conf. Note they are _not_ on your
subnet, so you must be routed to them via GW. These may or may not be
the same used when in Win.

> option dhcp-server-identifier 192.168.4.27;
This is the DHCP server where you acquired this lease. Renewals will
be sent directly here rather that via broadcast requests.

> option broadcast-address 255.255.255.255;
> renew 6 2004/4/24 05:23:46;
> rebind 0 2004/4/25 04:48:16;
> expire 0 2004/4/25 10:47:19;
> }
[snip]

First, browsers are _useless_ (almost) for diagnosing network
configuration problems. Observed behavior could stem from hundreds of
_browser_ differences irrespective of network problems. And no two
cache the same info.

Second, ping is not much better unless you know how to interpret the
results. As the Linuxforum guy said, Excite, eg., doesn't allow that
kind of traffic. Ping 127.0.0.1, then localhost, then your GW, then
your name servers to establish a _basic_ working network
configuration. Problems here must be corrected before anything else
will work properly or consistently.

When ping has you wondering, pull out your traceroute guns to follow
the actual path your packets are taking. Eg., traceroute to excite
would reveal where your ping packets are being dropped -- nothing you
can do about that and not your problem. The "failed" ping shows
nothing.

Third, _never_ change your network settings that were set via DHCP to
solve a problem. It's very tricky and ill-advised to do this to
investigate a problem -- you run the very real risk of "poisoning"
network data concerning your configuration that can be a real pain to
clear up. Remember, network traffic and data is two way -- routers
and servers are learning about you as you use the network. Eg., don't
change your GW by hand, nor your IP or masks or routing tables nor
your DNS name servers -- unless you know what you're doing and can
clean up afterwards.

Now, to your very real problems...

I'm not familiar with Charter and you may have to locate someone who
is to get good, consistent service from both Win and Linux. Right
now, the DHCP servers and routers and perhaps other servers see two
IPs bound to one MAC -- Charter's network may not like that. Routers
certainly don't -- it plays games with the arp cache.

One possibility is to change the MAC address in one OS -- Win is a
good candidate and in Linux it's almost too easy. That way, you'll
get one MAC-IP pair for Win and another with Linux. This may not work
because a) it will look like you're running two computers and you're
certainly using two IPs (which your account may not allow) and b) the
cable modem may not like handling two MACs.

Re: the last point, I'm not familiar with Toshibas and my web source
for such info is in the process of moving. Be sure you monitor the CM
configuration during this process to see how it behaves from Win and
Linux if you try this.

You can also set up your Linux sessions to request DHCP config info in
the same way that your Win sessions do if you use dhclient in Linux.
The config file can be set up to send the same client-id as Windows.
Thus you will always appear to the network to be using one computer
_and_ you'll actually only require one IP address. Try this for some
background:
http://homepage.ntlworld.com/robin.d.h.walker/cmtips/dhcp.html
I would have to look around to get the details -- J.M. may have them
handy.

After your networking configuration is "correct", then you can tackle
issues regarding browsers and email performance. Don't try to "fix"
it all at once -- you'll never know what changes are working and which
are not or making things worse.

My "gut" tells me that you'll probably need to make your Linux
sessions/DHCP requests look the same as your Win sessions. Just a
guess at this point, so don't take it to heart without investigating
further.

Hang in there -- you're doing good so far. Most would have given up
long ago.

hth,
prg
email above disabled

Relevant Pages

  • Basic Linux Network configuration
    ... Linux, like all other OSs, must have their Network ... devices to access the internet such as Linksys, ... "Expert configuration" and, ...
    (alt.os.linux.suse)
  • Re: Please suggest a Hardware Firewall and VPN solutions below $500.00
    ... with CheckPoint and/or Linux)? ... Assuming a simple network to network connection without future expansion ... I've used custom scripts with ssh certificates and pppd and vtun to do ... How does freeswan configuration compare ...
    (comp.os.linux.security)
  • Re: [SLE] HowTos for a home LAN
    ... I doubt you will walk across your house to turn on the linux box so your ... > Your biggest issue is establishing a configuration which will play with your ... a network requires a hub and a star layout. ...
    (SuSE)
  • Re: proxy network server configuration
    ... >> I have a Linux computer and two Windows 98SE computers. ... >network protocols, you need to do something like NAT (Network Address ... >ways of setting this up than others (configuration GUIs versus ...
    (alt.os.linux.redhat)
  • Re: network mapping tool
    ... In short I am looking for a program that can visual map my network and show ... should also detect routers and make links between nodes, ... >> several linux tools incl. ...
    (comp.os.linux.misc)