Re-enable telnet on Thomson TG585 v8 routers

A few months ago, I had successfully updated the firmware on my Thomson TG585 v8 router to version 8.2.7.8 when I also found out that I could connect to it via telnet, as per my previous post.

Recently, due to connectivity problems, my ISP requested that I perform a factory reset on the device. After solving those connectivity problems, I realised that access via telnet was not possible anymore. The weird thing was that I had not changed any settings on either router or computer, so this problem got really puzzling.

Finally, I found the reason why this was happening, as well as a working solution from member ZhenXlogic over the Greek forum at www.adslgr.com which I replicate here, in English, for those of you that could not easily find a solution, yet. The steps are easy.

First, save your current router settings by visiting the web interface over at 192.168.1.254 and selecting the left icon “Thomson Gateway”. Once inside, click on “Configuration” and then choose to “Save or Restore Configuration”. Then click on “Backup Configuration Now…” and select the location where user.ini will be saved.

Now with your favourite text editor, open the file user.ini and carefully browse inside, until you find the section [servmgr.ini] where you will see the problem itself: the new settings of the router have restrictions on the IP addresses that will access it via telnet, as seen in this output of mine:

[ servmgr.ini ]
ifadd name=PPTP group=lan
ifadd name=HTTP group=lan
ifadd name=HTTPs group=lan
ifadd name=HTTPs group=wan
ifadd name=FTP group=lan
ifadd name=FTP group=wan
ifadd name=TELNET group=lan
ifadd name=TELNET group=wan
ifadd name=DNS-S group=lan
ifadd name=MDAP group=lan
ifadd name=SSDP group=lan
ifadd name=PING_RESPONDER group=lan
ipadd name=HTTPs ip=212.251.87.4
ipadd name=HTTPs ip=62.1.46.29
ipadd name=HTTPs ip=62.1.46.30
ipadd name=HTTPs ip=10.24.11.19
ipadd name=HTTPs ip=10.24.11.20
ipadd name=FTP ip=212.251.87.4
ipadd name=FTP ip=62.1.46.29
ipadd name=FTP ip=62.1.46.30
ipadd name=FTP ip=10.24.11.19
ipadd name=FTP ip=10.24.11.20
ipadd name=TELNET ip=62.1.46.29
ipadd name=TELNET ip=62.1.46.30
ipadd name=TELNET ip=10.24.11.19
ipadd name=TELNET ip=10.24.11.20
ipadd name=TELNET ip=212.251.87.4
modify name=PPTP state=enabled
modify name=SNTP state=enabled
modify name=SLA_ICMP_PING state=enabled
modify name=SLA_UDP_PING state=disabled
modify name=HTTP state=enabled
modify name=HTTPs state=enabled
modify name=WEBF state=disabled
modify name=TFTP-C state=disabled
modify name=FTP state=enabled
modify name=TELNET state=enabled
modify name=RIP state=disabled
modify name=IGMP-Proxy state=enabled
modify name=DNS-S state=enabled
modify name=DNS-C state=enabled
modify name=DHCP-S state=enabled
modify name=MDAP state=enabled
modify name=CWMP-C state=enabled qoslabel=Management
modify name=CWMP-S state=enabled
modify name=SSDP state=enabled
modify name=GRE state=disabled
modify name=IPIP state=disabled
modify name=IP_COMMANDS state=enabled
modify name=PING_RESPONDER state=enabled
mapadd name=HTTP port=www-http
mapadd name=HTTPs port=443
mapadd name=HTTPI intf=LocalNetwork port=www-http
mapadd name=HTTPI intf=LocalNetwork port=1080
mapadd name=HTTPI intf=LocalNetwork port=httpproxy
mapadd name=FTP port=ftp
mapadd name=TELNET port=telnet
mapadd name=DNS-S port=dns
mapadd name=MDAP port=3235
mapadd name=SSDP port=1900

 
As you can see, unless you set the IP of your computer to the above specific values in highlighted red, the router will not allow access to its telnet console. For some reason, the developers of the Thomson firmware forgot to include the router’s default IP subnet, i.e. 192.168.1.xxx completely.

To remedy this situation, you simply need to add the line below as the first entry for TELNET, in order to allow the current router’s IP subnet (static or DHCP) computers to connect to it:

ipadd name=TELNET ip=192.168.1.[1-100]

 
In my example, I restrict the range from 1 to 100 but you can also set it from 1 to 200, accordingly. Therefore, insert this entry with your text editor back in the [servmgr.ini] section, like I did:

[ servmgr.ini ]
ifadd name=PPTP group=lan
ifadd name=HTTP group=lan
ifadd name=HTTPs group=lan
ifadd name=HTTPs group=wan
ifadd name=FTP group=lan
ifadd name=FTP group=wan
ifadd name=TELNET group=lan
ifadd name=TELNET group=wan
ifadd name=DNS-S group=lan
ifadd name=MDAP group=lan
ifadd name=SSDP group=lan
ifadd name=PING_RESPONDER group=lan
ipadd name=HTTPs ip=212.251.87.4
ipadd name=HTTPs ip=62.1.46.29
ipadd name=HTTPs ip=62.1.46.30
ipadd name=HTTPs ip=10.24.11.19
ipadd name=HTTPs ip=10.24.11.20
ipadd name=FTP ip=212.251.87.4
ipadd name=FTP ip=62.1.46.29
ipadd name=FTP ip=62.1.46.30
ipadd name=FTP ip=10.24.11.19
ipadd name=FTP ip=10.24.11.20
ipadd name=TELNET ip=192.168.1.[1-100]
ipadd name=TELNET ip=62.1.46.29
ipadd name=TELNET ip=62.1.46.30
ipadd name=TELNET ip=10.24.11.19
ipadd name=TELNET ip=10.24.11.20
ipadd name=TELNET ip=212.251.87.4
modify name=PPTP state=enabled
modify name=SNTP state=enabled
modify name=SLA_ICMP_PING state=enabled
modify name=SLA_UDP_PING state=disabled
modify name=HTTP state=enabled
modify name=HTTPs state=enabled
modify name=WEBF state=disabled
modify name=TFTP-C state=disabled
modify name=FTP state=enabled
modify name=TELNET state=enabled
modify name=RIP state=disabled
modify name=IGMP-Proxy state=enabled
modify name=DNS-S state=enabled
modify name=DNS-C state=enabled
modify name=DHCP-S state=enabled
modify name=MDAP state=enabled
modify name=CWMP-C state=enabled qoslabel=Management
modify name=CWMP-S state=enabled
modify name=SSDP state=enabled
modify name=GRE state=disabled
modify name=IPIP state=disabled
modify name=IP_COMMANDS state=enabled
modify name=PING_RESPONDER state=enabled
mapadd name=HTTP port=www-http
mapadd name=HTTPs port=443
mapadd name=HTTPI intf=LocalNetwork port=www-http
mapadd name=HTTPI intf=LocalNetwork port=1080
mapadd name=HTTPI intf=LocalNetwork port=httpproxy
mapadd name=FTP port=ftp
mapadd name=TELNET port=telnet
mapadd name=DNS-S port=dns
mapadd name=MDAP port=3235
mapadd name=SSDP port=1900

 
Notice the entries in orange, where TELNET is enabled for access via wired (lan) and wireless (wan) computers, at the default port 23:

ifadd name=TELNET group=lan
ifadd name=TELNET group=wan
modify name=TELNET state=enabled
mapadd name=TELNET port=telnet

 
Now that you’re at it, you can disable (unbind) the router’s SIP port mapping to allow your own SIP devices to work perfectly, as per my older post. Simply remove the line below from section [connection.ini] within user.ini:

bind application=SIP port=5060-5060

 
You can also disable the WPS functionality by setting the proper field inside [wireless.ini] section:

wps config ssid_id=0 state=enabled

 
to:

wps config ssid_id=0 state=disabled

 
Once saved, you need to upload the new configuration back to the router. Thus, you need to visit again the web interface over at 192.168.1.254 and select the left icon “Thomson Gateway”. Right under, click on “Configuration” and then choose to “Save or Restore Configuration”. Then click on “Restore Configuration Now…” and point to the modified user.ini to be uploaded.

The device will reboot in order to apply the new settings; in a couple of minutes, you shall have telnet access!

2 thoughts on “Re-enable telnet on Thomson TG585 v8 routers

  1. I have a question… I follow this steps (I only have telnet group=lan and telnet group=wan, so my modem has not telnet ip=62.1.46.29 and the others ip address) but I can not connect me to the web site anymore. Sorry for me english, I need to improve it.

  2. Hi there, this is an old article and I no longer have this TG585 v8 modem, so if you cannot access the setup page of the modem or Internet in general, you’d better do a hard-reset to the modem (and maybe start over).

    But you did not say what exactly you want to do. Normally, to allow Telnet (for specific actions, be careful) you’d save the default modem configuration, add 3 lines in the correct location, save it, upload configuration and restart. If you don’t have IP’s as the list above, it may be that your Internet provider changed the configuration of your modem.

    If you are sure that you have the exact same TG585 v8 modem, your default home IP range should be 192.168.1.xxx and the above steps are correct, these are the 3 lines to add: The first allows home/local IPs to login, the second enables Telnet itself, third sets default Telnet port to use (e.g. via Linux or PuTTY).

    ipadd name=TELNET ip=192.168.1.[1-200]
    modify name=TELNET state=enabled
    mapadd name=TELNET port=telnet

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