Weird Network Issue

[Morfiend]

Ok guys, once again I am coming to you for ideas on my work network. I didn't set up the network here so its hard for me to track down this problem. First I will give you the set up, and then the issue.

The setup is like this:

We have around 50 computers, with a mix of Static and Dynamic IP setups, and some of the Dynamics are wireless. We have one 8 port netgear prosafe router that is serving DHCP, we have a Apple Airport Extreme that is giving wireless but not DHCP.

We have 2x 24port gigE switches, and 3x5 port consumer switches that this is all running through. All the connections running DHCP are running through the router.

Now the issue is this. On machines that are using DHCP wired ONLY (machines using Wireless DHCP are fine), when loading a webpage with a whole bunch of thumbnail images, around 1000 or so, a LOT of the images (60%+) will time out, and not show up. It doesnt sound like a big problem, but for my work it is.


Any one have any ideas why this could be doing that for wired DHCP only and not wireless DHCP connections?

I know thats not much info to go on, but any suggestions on where to start looking would be great.

[schild]

Perhaps it's the fact you have 50 computers all running through two shitty consumer-grade....networking hubs in a photorich environment. It wouldn't shock me if one, or both, pieces of hardware was near death. Seriously, get some gigabit switches up in that shit and stop buying your hardware on sale at Fry's.

We require more information.

[Yegolev]

Any one have any ideas why this could be doing that for wired DHCP only and not wireless DHCP connections?

Stock firmware?  What sort of router is this?  How about setting statics on all the wired machines since there seems to be some sort of wackyness between the airport and the linksys... assuming the linksys is not also doing wireless.

[Ingmar]

Do you have the same problem if you give the machines fixed addresses?

A network diagram would be helpful too, fire up MS Paint!

[Yegolev]

We require more information.

I suspect you nailed it the first time.

[Salamok]

How are the switches stacked, you shouldn't really nest em more than 3 deep (I'd even avoid going more than 2 deep).  Are your 2 24x switches chained together properly or do you just have some cat5 connecting them?  Are you sure every single DHCP configed computer has this issue, how many switches are your computers generally hopping through to get to that switch acting as a DHCP server?

More info is definitely in order, but I call dibs on a switch stacking/chaining issue, something like internet/router=>DHCP switch => airport hub => 24xgig1 #1 => 24xgig2 => random crap mini switch out on the floor => computer would cause issues.

edit:  also cheap switches generally don't have enough backplane to support all of their ports at max capacity, you may be better off forcing everyone to talk at 100mbs.

[Morfiend]

More info is definitely in order, but I call dibs on a switch stacking/chaining issue, something like internet/router=>DHCP switch => airport hub => 24xgig1 #1 => 24xgig2 => random crap mini switch out on the floor => computer would cause issues.
100mbs.

Im going to try and get a graph up a bit later.

Basically, it doesnt matter where the computer is located on the network, if it is using DHCP wired, it will have this issue, and if I change it to static IP, the issue goes away. This leads me to think there is some kind of configuration issue somewhere on the network.

[fuser]

Basically, it doesnt matter where the computer is located on the network, if it is using DHCP wired, it will have this issue, and if I change it to static IP, the issue goes away. This leads me to think there is some kind of configuration issue somewhere on the network.

is your dhcp/static netmask/gateway the same? also are you dhcp clients picking up a proxy server in internet explorer or such?

[Trippy]

Are the thumbnails from diffferent hostnames or are they all from the same site?

[Morfiend]

Are the thumbnails from diffferent hostnames or are they all from the same site?

All from the same site. My companies website. Also, under some browsers, they dont time out, they just take FOREVER to load. We are talking like 20 minutes to load in 1000 thumbnails.

[Morfiend]

is your dhcp/static netmask/gateway the same? also are you dhcp clients picking up a proxy server in internet explorer or such?

Just checked. the Subnet Mask's are different. Anything running DHCP is 255.255.255.0 and anyone running static is 255.255.255.192, but I dont think thats the issue as running wireless DHCP works fine, and it has the .0 netmak.

[schild]

Are the thumbnails from diffferent hostnames or are they all from the same site?

All from the same site. My companies website. Also, under some browsers, they dont time out, they just take FOREVER to load. We are talking like 20 minutes to load in 1000 thumbnails.

Just out of curiosity, how did someone decide to have something insane, like, 1,000 thumbnails load? I mean, even by itself, that's a design flaw.

[Morfiend]

Are the thumbnails from diffferent hostnames or are they all from the same site?

All from the same site. My companies website. Also, under some browsers, they dont time out, they just take FOREVER to load. We are talking like 20 minutes to load in 1000 thumbnails.

Just out of curiosity, how did someone decide to have something insane, like, 1,000 thumbnails load? I mean, even by itself, that's a design flaw.

Well, we are an image archive agency, and some times people need to go through a lot of images at a time.

[schild]

Are the thumbnails from diffferent hostnames or are they all from the same site?

All from the same site. My companies website. Also, under some browsers, they dont time out, they just take FOREVER to load. We are talking like 20 minutes to load in 1000 thumbnails.

Just out of curiosity, how did someone decide to have something insane, like, 1,000 thumbnails load? I mean, even by itself, that's a design flaw.

Well, we are an image archive agency, and some times people need to go through a lot of images at a time.

1,000 though?

Isn't this the sort of thing you'd want to automate, say, load the first 50, when you scroll to the bottom, load the next 50. Also, shouldn't you all be running squid on your end and caching all of this stuff so this sort of thing isn't an issue?

[Morfiend]

Are the thumbnails from diffferent hostnames or are they all from the same site?

All from the same site. My companies website. Also, under some browsers, they dont time out, they just take FOREVER to load. We are talking like 20 minutes to load in 1000 thumbnails.

Just out of curiosity, how did someone decide to have something insane, like, 1,000 thumbnails load? I mean, even by itself, that's a design flaw.

Well, we are an image archive agency, and some times people need to go through a lot of images at a time.

1,000 though?

Isn't this the sort of thing you'd want to automate, say, load the first 50, when you scroll to the bottom, load the next 50.

When your trying to edit a lot of images, doing pages of 50 is a nightmare. Also, I agree with you that there are better ways to do it. But it is what it is, and its not going to change, so I just need to fix the issue. Also, it only effects a few people, but the main person it effects is the owner of the company, so....

[Yegolev]

....so give that guy a static IP.  Bada-bing, you survive the New Economy.

[Morfiend]

....so give that guy a static IP.  Bada-bing, you survive the New Economy.

I already did that, but it does effect other people too, and it bugs me that the network is not working correctly.

[Lantyssa]

Is the server feeding the pictures internal to this network?

Is it static?  That netmask difference might be causing oddities if they're essentially on the same router.

[justdave]

Does changing from DHCP to a static IP clear it up, no matter which switch the attached machine is on? When you change people to the /26 addresses do you move them to a different switch/port,etc, or do you just change them to a static scheme in their local config and things get better?

EDIT: Also, yes, netwerk drawink, please. :)

[Numtini]

Give someone a static with the limited netmask and see if that repilcates the DHCP issues. Is there a reason for the netmask or lack thereof?

[Morfiend]

or do you just change them to a static scheme in their local config and things get better?

Correct, no change in any hardware, just setting a user to a static IP will clear up the issue no matter where on the network they are physically located. Wired static, if they are wireless on dhcp the problem does not happen.

[Morfiend]

Give someone a static with the limited netmask and see if that repilcates the DHCP issues. Is there a reason for the netmask or lack thereof?

It had no effect, was able to load fine.

[Lantyssa]

Correct, no change in any hardware, just setting a user to a static IP will clear up the issue no matter where on the network they are physically located. Wired static, if they are wireless on dhcp the problem does not happen.

The wireless users are getting their address from the AirPort though, which I assume has a fixed IP.

Do DHCP machines have trouble connecting to other DHCP machines?  I really don't like that netmask set up.  Set some static machines to 255.255.255.0 and see what happens.

[Salamok]

could the AirPort be issuing conflicting addresses that somehow instead of resulting in the "You are using an ip address that is in use by another device...." message is just stealth snatching it in a way that interrupts network traffic.  Check to make sure that the address ranges being issued by your wired DHCP box and the AirPorts DHCP don't overlap.  Or maybe just turn the AirPort off entirely to see if your problem goes away, shutting down all unnecessary networkable equipment may be a good troubleshooting checkpoint as well.  After hours, turn off all equipment (ie other computers, switches, hubs that this computer is not reliant on) except for 1 problematic computer and the switches it is routed through to get to the internet.

[justdave]

I'm presuming that the /24 DHCP net and the /26 static net don't overlap, also correct?

EDIT: Just to verify, the DHCP server is handing out the same default gw as is set when they're statically confiigured?

EDIT2: lrnd2read

[Morfiend]

could the AirPort be issuing conflicting addresses that somehow instead of resulting in the "You are using an ip address that is in use by another device...." message is just stealth snatching it in a way that interrupts network traffic.  Check to make sure that the address ranges being issued by your wired DHCP box and the AirPorts DHCP don't overlap.  Or maybe just turn the AirPort off entirely to see if your problem goes away, shutting down all unnecessary networkable equipment may be a good troubleshooting checkpoint as well.  After hours, turn off all equipment (ie other computers, switches, hubs that this computer is not reliant on) except for 1 problematic computer and the switches it is routed through to get to the internet.

This is one of the things I have wondered, and am meaning to test. Although I feel like I did test it and it didnt help. I did a bunch of tests 2 months back and could never find the issue, I am pretty sure I did this, but will do it again just to make sure.

[Morfiend]

Correct, no change in any hardware, just setting a user to a static IP will clear up the issue no matter where on the network they are physically located. Wired static, if they are wireless on dhcp the problem does not happen.

The wireless users are getting their address from the AirPort though, which I assume has a fixed IP.

Do DHCP machines have trouble connecting to other DHCP machines?  I really don't like that netmask set up.  Set some static machines to 255.255.255.0 and see what happens.

I just checked the airport setup. Two things:

1) It is set to be DHCP. So its getting its address from the other router.
2) It is NOT giving out IPs. Its only bridging the connection.

So confused.

[Yegolev]

I'm pretty sure you would just want one DHCP server.  Not that I'm a networking guy.  Also, if it was me, I'd give the Airport a static.  I'd also have everyone using the same mask.  With the Airport just bridging, I'd look at everything in relation to the Linksys config and therefore have all the clients configured identically.  Maybe someone more experienced in packeteering can correct me.

[Lantyssa]

I just checked the airport setup. Two things:

1) It is set to be DHCP. So its getting its address from the other router.
2) It is NOT giving out IPs. Its only bridging the connection.

So confused.

Okie.  That's fine.

So the wireless DHCP are not having the problem but the wired DHCP are.

What is the full network info for a wireless machine and a wired one?  "ipconfig /all"  What's different between them besides IP and where they are on the network map.  Eliminate those possibilities first.

[Viin]

Okie.  That's fine.

So the wireless DHCP are not having the problem but the wired DHCP are.

What is the full network info for a wireless machine and a wired one?  "ipconfig /all"  What's different between them besides IP and where they are on the network map.  Eliminate those possibilities first.

And then slaughter a young bull. Make sure it's all one color, no blemishes. And use a knife made of pure bronze. And it has to be at noon exactly, so don't forget to adjust for Daylight Savings.

Then see if it works.

[Lantyssa]

He needs to eliminate variables and we don't have enough info yet to say "it's this".  We're still waiting on a network map.