Networking Issue

H

HairyHun

Masturbating Bandit
Oct 11, 2007
576
2
0
We have a T3 that's hooked to my router.
The provided gives me 5 mbps up & down.

In the beginning things went well but for about 3 weeks now I have the following problem.

A website sometime refuses to load. Once it times out, if I do refresh it loads right away.

If a page decides to go that route, there is nothing i can do but wait for the timeout. If i try refreshing, or opening it on another browser, I get the same result.

I tried resetting the router, no help.

Any idea what would be the issue? Or how i can isolate the source of the problem?

Thanks
 


Have you done any pinging to see if it's a bigger network issue?

Is there a regional POP issue? Some parts of world come up, others do not?

How long has this been going on?

Have you tried to clear cache, close out all your browsers, refresh your IP?

Have your run malware, and spyware cleaners?
 
Get the MAC addresses or interface names of your gateway's WAN/LAN ports and search the logs to see if any of the links are going down and subsequently back up.

Also, are you running your own DNS server or only using your provider's?
 
Barefootsies said:
Have you done any pinging to see if it's a bigger network issue?

Is there a regional POP issue? Some parts of world come up, others do not?

How long has this been going on?

Have you tried to clear cache, close out all your browsers, refresh your IP?

Have your run malware, and spyware cleaners?
Click to expand...

1. I did a traceroute at the moment where it's going on and there is timeouts like hops down. The same thing happens when it's loaded properly AND from a backup DSL connection too.

2. All the websites come up, either right away, or if a do a refresh after the timeout. Basically if it doesn't load right away, it will time outa nd then it will load after.

3. Tried empty cache, reboot router (not a hard reset), different computers and restart computers.

4. This begun about 3 weeks ago



I'm thinking I'll go to the server room and connect my computer directly to the uplink and see if we get the same thing. This way we can elimitate the router from the possible culprits
 
jryan21 said:
Get the MAC addresses or interface names of your gateway's WAN/LAN ports and search the logs to see if any of the links are going down and subsequently back up.

Also, are you running your own DNS server or only using your provider's?
Click to expand...


DNS: we are getting it from our provider.

The logs, within my router? This part is beyond my skill level but I'll look into it.
 
HairyHun said:
We have a T3 that's hooked to my router.
The provided gives me 5 mbps up & down.
Click to expand...

Network issues:

- Are you having a traffic spike? Look at the router's traffic stats to see if you have congestion. Look at the interface counters to see if you've got drops
- Since it's a TDM circuit, look on the CSU for slips or other errors. You could also request the carrier do the same, if you suspect line errors.
- Capture the traffic with wireshark to figure out why the request is timing out. Usually you're looking for retransmits, dup acks, and zero windows.
- Ping across the link to the router's next hop. Don't worry too much about traceroutes at this point. Throw 100 packets down the line and see how many came back and what the latency was.

Other:
- Is it a certain element on the page that's holding up the load? For example, a third part ad network? Firebug will tell you the element that's doing it -- it might not even be on the site itself. From there, it could be reachability issues from your ISP to the host

Monitoring:
Use MRTG at a minimum. Smokeping for bonus points.

Sean
 
I am having the exact same issue, but only with the wireless LAN. The desktop attached directly to the router is fine, but the wireless behavior is the same in every detail to what OP describes. Have yet to find a solution.
 
DanWesson said:
I am having the exact same issue, but only with the wireless LAN. The desktop attached directly to the router is fine, but the wireless behavior is the same in every detail to what OP describes. Have yet to find a solution.
Click to expand...

2.4 or 5GHz? Most likely cause is interference... Try changing to a different channel (1/6/11), or if you've got some performance extensions turned on, turn them off (eg 40MHz channels or bonding). Move the router around, either closer to where you're working, a different part of the home/office, or even just changing the orientation or getting it off of whatever platform it's on.

Sean
 
SeanW said:
Network issues:

- Are you having a traffic spike? Look at the router's traffic stats to see if you have congestion. Look at the interface counters to see if you've got drops
- Since it's a TDM circuit, look on the CSU for slips or other errors. You could also request the carrier do the same, if you suspect line errors.
- Capture the traffic with wireshark to figure out why the request is timing out. Usually you're looking for retransmits, dup acks, and zero windows.
- Ping across the link to the router's next hop. Don't worry too much about traceroutes at this point. Throw 100 packets down the line and see how many came back and what the latency was.

Other:
- Is it a certain element on the page that's holding up the load? For example, a third part ad network? Firebug will tell you the element that's doing it -- it might not even be on the site itself. From there, it could be reachability issues from your ISP to the host

Monitoring:
Use MRTG at a minimum. Smokeping for bonus points.

Sean
Click to expand...


• Traffic spike: I don't think so. we have 8 pcs doing browsing and about the same number of VOIP phones. The issue is consistent whatever the computers might be doing

• When you say ping the next hop, you mean do a traceroute out , see the first hop and ping them?

• I checked the logs in the router ( it's a RV082 ) i see some Connection Refused - Policy violation errors

• It's not a third party element. Usually either whole page loads fast, or the hole page does not (in which case, one i get the timeout, it will load fast ).

In other cases, the page is very slow to load and doesn't finish loading completely ( css is missing, half the pics are missing, etc ). In which cases i need a few refresh before all is back well.

• CSU and wireshark, those are beyond my jedi skill level so I'll google that and report back.


Thanks for you help
 
HairyHun said:
• I checked the logs in the router ( it's a RV082 ) i see some Connection Refused - Policy violation errors


Thanks for you help
Click to expand...

Looks like there might be an issue with the router's firewall. You can confirm this by plugging a computer directly to the uplink and not having the same issues.

What port are you getting it on? Usually in the log it will have IP Address:Port
 
This is the current setup.

RV082 is the server room, connecting to plugs in the wall.
There is an Apple Router operating in Bridge mode connected to the wall. It's our wireless base station


I did some extensive testing and these are my findings.

• The computers currently are experiencing the following issues
a) One has the dropped connection like mine, but only once and hour
b) Others have slowdowns ( takes a while to load, but ends up loading )
c) There is one PC that's lightning fast on the internet

• I tested the wireless compare to straight to the wall. Similar performance.
At one point some pages just wouldn't load at all ( immediate error ) from the wall plug. I connected to the wireless it started working. I suspect a DNS issue. Strange.

•GAYThere is a PC that has been on for days that's wired to the Airport Router. The net is lightning fast on that. So I figure the bulk of the problem is not upstream.

• I started tracking the loading times and breakdown using firebug and the NET feature.

On my laptop the first time i load a website i lose a LOT of time with the DNS lookup. Subsequent navigation of the same site is pretty fast. Although sometimes slows, but still loads. I got some files that take 7-12 seconds for the

When I come thru firebug using the PC, things are fast. But I'm not sure if this is an orange-for-orange comparison tho.

• When I check the log and i have that time-tout and subsequent succesfull reload, there is no error in the log ( i tracked using the IP)



Bottom line: There seems to be an issue with the DNS lookup on my laptop. Is it software? Os? Browser? Is there a tool to narrow down that particular issue?
 
Assuming the clients point to the bridge as the default gateway-

Are the router's clients connected via DHCP or static IPs?

In their network configurations, do the LAN clients use a DNS server on the router or are they using the DNS servers of your provider?
 
The Bridge does that automatically I think, we just set it as bridge.
All clients are connected using DHCP except our local test server

For the DNS server I'll check when I get to the office and report back.
I think it's on whatever is the default configuration in these cases.
 
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