Port blocking creates confusion for NTL customers
Last month NTL took the decision to block ‘port 135′. ntl:home is now blocking more Internet ports to reduce the threat of new virulent worms that may use these ports to spread across the Internet.
The NTL web site states that “This “port-blocking” should have little or no effect on your use of the Internet but it will significantly reduce the vulnerability to infection from variants of the Welchia and MSBlast worms.”
The ports being blocked (inbound only, to stop infections) are: 137 (UDP), 138 (UDP), 139 (TCP), 445 (UDP & TCP), 593 (TCP), 1433 (TCP), 1434 (UDP), 27374 (TCP)
One NTL user told Net4Nowt “NTL took this step without any prior notification. At present there is still no direct link to the info on their site. I can understand the aim but the implementation leaves a lot to be desired. I imagine support staff up and down the country scratching their heads and wondering why the manager’s laptop never gets the sales figures when he works from home, or why a social worker can’t successfully update a client case file after a visit.
In my own case I spent 4 days trying to figure out why I could no longer reach the SQL server on my web site, before discovering this by a process of elimination.
When I contacted the NTL help desk the (very pleasant) support person did not believe me that NTL would do this. He was especially surprised because the support staff hadn’t been briefed.”
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