Weird router problem
 

I searched and am fairly sure my problem is unique.
I have earthlink DSL access in Seattle. The problem is that when I use a router or a router/switch (Hawking Technologies PN9225 or Asante FR3000) I can't do certain things. I have a dynamic IP (But that shouldn't be relevant...)

1. I can't access half.com or ebay.com, other sites flat out work fine. I also have trouble shopping online. In general interactive sites don't work well. When I click on certain links the browser reports that "the page contains no data"

2. I can't post in vbulletin forums nor any other as far as I know

3. I can't send email from my mac for some weird reason. PC works fine with the exact same accont. (SMTP)

4. I can't perform an FTP install of SUSE linux. It times out doing DHCP (3com 3c905, should work...) and when I specify the ip manually it can't connect to the ftp server.

If I connect any one machine directly to the DSL modem these problems disappear. I have no clue...
I have tried the Gamut of OS's on this one and they all react differently, but usually have some problems in common.

Sounds like an IP conflict or corrupted ARP cache. If there are several machines hooked up to the same switch, are you positive they all have unique IPs and their netmask is correct?

If you are using several machines, are you using rfc 1918 private IP range (10.10, 192.168, etc) for each machine?

If the switch itself is acting as a DHCP server, I would check carefully that this is configured correctly. You may want to reset the switch to factory defaults before proceeding. But unless I am mistaken, you are saying that you see this behaviour with two *different* switches entirely, so I would look to the client configurations before I started mucking with the switch.

The problem exists in multiple routers
 

And all the DHCP settings are correct.
Like I said, it works for a the majority of other protocols and purposes. But not for a few critical ones.

I also wouldn't blame client configurations as it exists in Linux, WinXP and OS X.

The linux and OS X boxes have worked behind a variety of other switches and routers flawlessly.

I'm at a loss then. Although, I wouldn't trap myself into thinking the OS has any significance. The network layer doesn't care about the OS. If there is an IP conflict or incorrect netmask settings somewhere on the LAN, it's going to effect routing in unpredictable ways.

Try configuring all your clients manually and carefully select ip/netmask/route settings.

I can't help troubleshoot your setup beyond these suggestions without a detailed description of the LAN and how it is configured.

In more detail,

Router plugs into DSL modem, and then into a hub.
I don't touch the routers settings at all. It is giving the IPs through DHCP and all the computers pick them up fine and are able to browse and operate normally with above mentioned exceptions. It all conforms to all the regular standards, this is all pretty plain vanilla. Nothing fancy going on which is why I am at a loss.

This occurs with two routers. (Models mentioned above)

The DSL modem is broadmax, not that it is relevant. (since the problem exists in the router)

This occurs in multiple OS's on multiple platforms.
Specifying the IPs manually doesn't help either. They perform regular functions fine, but when I try and do the above four things they still don't work.

If one of the client machines is unix, what does "arp -a" output look like?

Grumble...
 

Have to reset the modem... plug back in the router... Give me 5

This situation was with only the WinXP machine, and the OS X machine on the network. The arp -a output is from OS X. The linux box is what I want to do the FTP install onto, I don't have a real distro yet, just the installer (which doesn't work through the router, but can start when directly connected to the modem.) The linux box was unplugged.

The physical situation is as described above with the router plugged into the 8 port hub which was connected to the two computers.

On the unix box, can you also paste the output of

# netstat -rn | grep default

and

# ifconfig -a

Okay, for this one I switched to a diff router, so the arp -a output changed slightly. This is the router I would like to get working with network. It is the Hawking Technologies PN9225 Single Port router (1 WAN port/ 1 LAN port) It is connected to the 8 port hub and DSL modem.

The output for all those commands is as follows
Thanks in advance, I know there isn't much to work with in this problem.
Don't stay up late waiting for me to reply after this post. I will pick it up again in the morning. Sleep now!

Hmm. That looks perfectly normal. Just to confirm a couple more things:

- Is your router plugged into the uplink port of the hub? Uplink port is usually set apart slightly from the others or labeled "Internet".

- In the above setup, are there any other client machines on the LAN? If so, does unplugging all but one have any effect on the behaviour of the remaining client?

I'm still at a loss, but given that you have the same symptoms with two different routers entirely, I still suspect the problem is something else. Your OSX client looks properly configured.

It is plugged into the uplink port, and the wire crossing button thingy is on the right setting (if it were wrong, it wouldn't connect at all)
Having a single machine doesn't change anything.

And completely unrelated... w00t! Made it to crazy...

I don't have a specific answer, but I'll throw my hat in to try to help.

Do both of these routers have a built in firewall? You said most traffic flows in and out okay, but certain protocols don't make it. Shopping sites, e-mail, and ftp all require some sort of authentication, right? I know that secure websites, outlook express, and some ftp sites will all have problems with SSL. I'm not saying this is your problem, but it sounds like your traffic is being filtered and that traffic seems to be security oriented.

If these routers have a firewall, I assume that there would be a way to turn it off. If I were you, I'd probably do that and then install a software firewall. I'm sure you could then monitor the traffic through the logs to find out what's being filtered or not and apply that to the two routers.

I know I didn't solve the problem, but I hope I sent you in the right direction. Good Luck

Router manufactuers are evil...
 

VERY VERY EVIL...
It was the max MTU size... the router couldn't handle large packets... IT SHOULD BE ABLE TO... only a TOTAL A** hole would advertise a router to be fully functional and then only provide partial support for the TCP/IP protocol which is a total load of crap... I am amazed this hasn't let to lawsuit hell before...


What amazes me is this occured in FOUR consumer level routers... I mean WTF everyone is producing this semi-functional crap... It's not like it's a big engineering or hardware cost to produce a fully functional controller... Just a little bit more memory and state involved...

Well, the ethernet spec states that a packet can't be larger than 1500. DSL routers add 12 in overhead, so you sometimes have to scale your MTU down to compensate.

:crazy:

That puts me in my place.
I still remain disappointed that professional techs from both the router and ISP weren't able to spot an obvious issue like this. I don't deal with networks often unless I program them myself (and then for some silly reason they always work :-P)

It shouldn't have taken me this long... the issue should be documented with the router or on the manufacturers site as I am downright positive this must come up often. How many thousands of customers use earthlink DSL and these name brand routers on plain jane XP installations... It happened on linksys, d-link, asante, and hawking routers! Not one of them has it documented and techs at Asante and Hawking don't know about it either.... I only found out by running randomly generated packets through the router overnight... I had to phrickin code it myself... sheesh...

I didn't catch that either. It's not a terribly common problem, but a known one. I agree, tech support for the router company should be able to troubleshoot this sort of issue. Tech support tends to be pretty bad in general, because people that really know their stuff move on quickly. Support is an entry-level (and much maligned) position for someone who has real technical knowledge.

But the company should know about this issue and its symptoms, and train their employees accordingly.

Re: Router manufactuers are evil...
 

Buy Cisco kit...

:)

BTW, what LinkSys box did it occur on? I'd be surprised if their kit did "not support" max MTU size.

Can you be more specific?


Mr Mephisto

An MTU size of greater then 1470 on any of the computers meant that some packets (of this large size) wouldn't pass through the router. I check by pinging the router with randomly sized packets, and by trying to pass randomly generated packets through it. Only some web sites trigger the transfer of large packets.

The linksys router and D-link router were on loan for the day, don't have them anymore so I can't test them anymore. The problem existed on the linksys router, but I didn't pass packets through it, I fixed the problem on the Hawking router which is a very old discontinued model that I got cheap.

On the hawking router if I pinged or sent a packet of size 1480 or larger then the packet would not arrive or in the case of ping it would say something about fragmentation. When I set the MTU to 1470 all apps work fine.

The linksys router was what looks like a rather old single port model.