Diffs between v8 and v7 of Thomson TG585v7 router (downgrade due to VPN PPTP)

[#1]

Hi Folks,
Yesterday, I become a proud  owner of the TG585v7 router Thomson router  - as a new Plusnet customer, who had their Broadband enabled today.
I sometimes work from home and was ensuring VPN connectivity when, I hit a little snag - my company uses PPTP for authentication purposes - after a quick check on the Plusnet newsgoups, I found the following article (thank-you BTW);
http://community.plus.net/library/hardware/how-to-upgradedowngrade-the-firmware-on-the-thomson-585v7...
I quickly downgraded the ADSL router to v7 and now I can connect via VPN as required.....
..question is  - are there any issues I need to be aware of, now that I am running on an older version of the f/w.
Thanks...
M

[#2]

...another question  - can I add in in manual entry portmap (on the Thomson) , for TCP 1723, opening protocol ID 47, to allow PPTP traffic through - if I need to upgrade back to version 8 of the f/w.
'A PPTP connection will fail if the firewall/router blocks GRE, which is protocol 47'

Even though PPTP is not 'supported' on the latest firmware, will opening up the respective ports in v8 resolve the issue - in connecting the VPN server, though I was under the assumption the router would have already allowed a client connection through anway, and my only real fix is to stay with v7.
Thanks.
M

[#3]

Hi, sorry for the delay in replying to this!
The main difference between the two is that v8 fixes a security flaw.  You can stop the flaw from affecting you by  making sure you have a username and password for the router.  Otherwise the differences between the two are mainly cosmetic (and the lack of PPTP!).
I'm not sure if opening/forwarding ports will solve the problem on the current version of the  v8 firmware, I'll check with Thomson and get back to you, this will probably be next week.

[#4]

Quote

...another question  - can I add in in manual entry portmap (on the Thomson) , for TCP 1723, opening protocol ID 47, to allow PPTP traffic through - if I need to upgrade back to version 8 of the f/w.

I don't think its quite that simple. A PPTP VPN tunnel uses communication on TCP port 1723 to the server to initiate and manage a second GRE tunnel to the same peer.
The TCP control channel is not a problem since its an outgoing connection and will be handled by the normal NAT translation but you need to get the firewall to allow GRE through. I'm not sure you can do that without the PPTP ALG , which was removed in v8. Maybe if you read up on the CLI for the TG585 you might be able to do it.