Re: Randomly blocking ports and IPs
 

Router.....doubt it, but one thing I have learned is never ignore doubts. Try a direct connection to the modem first, that saves any port triggering changes needed to be performed in the router to try and resolve this, no point in all that work if a direct connection can confirm its a router issue.

The server I used was cdn-kmr-c2100-01.tm.net.my:3128, try using that as an HTTP proxy, then visit http://www.whatsmyip.org/ to test it.

Re: Randomly blocking ports and IPs
 

Joxer - Tried a direct connection - that didnt weork either, but it was a good simple suggestion thats eliminated one possible issue

---------- Post added at 12:47 ---------- Previous post was at 12:44 ----------

Hi Toto, thanks for giving me the proxy you were able to use. This doest connect for me - same as all the others.

Proxies are working on ports other than 3128.

I also tested another computer on a direct connection, just in case it was something on the computer.

Im running out of possible solutions :(

Re: Randomly blocking ports and IPs
 

Hmm, a quick google suggests that tracert won't allow you to specify port or protocol - you are stuck with ICMP - I take it you are using windows? You could try telnet it allows you to specify the port.

Obviously using your own proxy and port number, just to see if it will connect - you won't be able to do anything if it does - type quit to exit.

Trying this on the above proxy and a random port just times out eventually so I doubt you will get any useful error message if it fails unfortunately, but you never know.

Re: Randomly blocking ports and IPs
 

Hi Joxer,

Telnets and raw connections time out on any connection I have tried to port 3128.

Connections to other ports on the same IP's work fine.

At this stage I beleive the following (feel free to correct me):

1. The proxies are not at fault (tested externally working 3rd party ones they also fail - and my private ones work for other users)
2. Only port 3128 is blocked, 80, 8080, 25 etc etc all work
3. Computer setup is not at fault (tried multiple computers)
4. Router is not at fault (bypassed it)

I dont see where else the problem could be other than with Virgin - any one have further suggestions?

Re: Randomly blocking ports and IPs
 

webcache.blueyonder.co.uk usually uses port 8080 but allows connections from here on 3128. It runs on squid and 3128 is the standard port for squid, it may be worth checking if your proxies allow use of other ports.

Interestingly webcache.virginmedia.com also allows connections on 8080 and 3128 but outputs an invalid request on exit however webcache.blueyonder.co.uk only outputs the message on port 8080 only. I am assuming that this means that the VM webcache allows use of both ports but the BY one doesn't, but I am guessing.

I am almost bored enough to test this theory.

Re: Randomly blocking ports and IPs
 

zen, do you have a business or residential account?

If business, would this count as breaching the SLA? (if it is in the VM network).

Re: Randomly blocking ports and IPs
 

He is EX-NTL going by the 86 IP so webcache.blueyonder.co.uk will probably not work.

Re: Randomly blocking ports and IPs
 

Residential :(

I will test setting up a new squid proxy later today on an alternate port. Such a hassle for something that should just work.

Its also a terrible shame that my experiences with support thus far have been polite but reasonably useless. I miss the days of tech support staff actually knowing something.

Moldova is excluded from the previous statement - his reply to my post was great :)

Re: Randomly blocking ports and IPs
 

I had spotted that, I wasn't suggesting he used them - he needs the proxy in a foreign country, merely suggesting that since another squid proxy worked on port 8080 and 3128 it may be worth trying port 8080 since this is not blocked.

I tested the blueyonder proxy and it works on 3128 as well so bang goes above theory.

Re: Randomly blocking ports and IPs
 

I think the blueyonder one just redirects to the virginmedia one anyway.

Re: Randomly blocking ports and IPs
 

D'oh, so it does, and getting consistent errors now too.

Re: Randomly blocking ports and IPs
 

I guess the other thing to test then are the Proxies that zen63 has set up, any chance of one we could look at?

---------- Post added at 15:25 ---------- Previous post was at 15:16 ----------

That actually is a good point, if there is the remote possibility that even at the local CMTS level there is some port blocking in place, on a business account this wouldn't be acceptable.

Re: Randomly blocking ports and IPs
 

If he access to a linux box on his home connection he can use tcptraceroute which uses TCP instead and lets you set the port to use too.

Re: Randomly blocking ports and IPs
 

No need for tcptraceroute latest traceroute has -T for tcp and -p to specify the port. I would suggest trying a live linux cd but can't gaurantee traceroute to be installed - fairly sure it isn't in Mandriva (which I use), I jsut tested Puppy linux and the version of traceroute is the one in busybox and only allows UDP pings though you can specify the port. Knoppix STD would prbably do it (STD stands for Security Tools Distribution) as it has a whole bunch of network tools.

Re: Randomly blocking ports and IPs
 

Went out for the afternoon - came back - and like magic the proxies work once more. Didnt restart computer or anything.

Strange problem, I think i will invest in a second bb line - i like virgins speed, but if a problem like this happens at the wrong time - its a major headache.

Thanks all of you for the help.