Draytek Vigor 2760n dial-in VPN update

Just spotted a useful firmware update from Draytek for their Vigor 2760 / 2760n / 2760Vn range which adds an important VPN feature.

In a previous article on the Draytek 2760 I mentioned that although the early revision of the hardware (which uses firmware 1.x) has dial-in VPN support (PPTP, L2TP) the later hardware revision with firmware 3.x didn't provide dial-in VPN. Got caught out by that change before!

Guess what Draytek fixed with the 3.8.2.1 firmware - they've added support for SSL VPN Remote Dial-In user connections. Excellent news - will be testing as soon as I get opportunity.

Draytek Vigor 2760 respond to ping on WAN internet interface

Setting your Draytek Vigor 2760 (or 2760n or 2760Vn) to respond to pings from the internet isn't very obvious. Note this was on my 1st gen 2760n, so firmware v1.2.1.2 - hopefully the 2nd gen with v3.x.x firmware series works the same way. I don't have one to hand to check, so let me know ...

Normally on a Draytek (such as 2830, 2850, 2860 etc) you go into System Maintenance > Management and untick the 'Disable PING from the Internet' box. On the 2760 series that check box doesn't exist. Its still the same menu option, so:

System Maintenance > Management
then for Management List you have to click the + symbol
and move the 'Ping' item from Available to Selected,
for your specific Internet interface (in this case the DSL PVC1)

Simple when you know where to look for it, see diagram.

Note that its worth leaving this off unless you're using it for testing or maybe uptime monitoring.

The other interesting point about the different models of the 2760 is that the older firmware model supports remote dial-in VPN users, whereas the newer v3 doesn't (I think it has LAN-LAN VPN iirc).

Draytek 2820 not connecting to Vigor 120 ADSL modem on WAN2, no response from server

Got a DrayTek Vigor 2820 router on the latest 3.3.7.5 firmware. We've got Plusnet connected using the ADSL WAN 1 port, which works fine. However WAN2 was connected to a Technicolor TG582n in ethernet bridged mode to ZEN broadband. WAN2 started dropping randomly and we couldn't pin down why.

We swapped a Draytek Vigor 120 ADSL modem (3.2.6.1) in place of the Technicolor. Line sync was ok, in fact faster than the TG582n, esp the uplink which doubled up from 512k to 1Mbps. Bonus! However it wouldn't connect from the 2820 router using the WAN2 PPPoE setup. This is a PPPoE to PPPoA bridged mode.

On the Online Status > Physical Connection you could see the PPP connection starting, but followed by a 'No response from the server' error.

Took a little while to identify - make sure the Vigor 120 modem has DHCP enabled on the LAN screen. Doh!

DrayTek Vigor 2820 ADSL monitoring with SNMP, whats the line speed OID

One client with a DrayTek Vigor 2820n internet router has a problem with the ADSL upload speed slowing down to around 40-50% of normal on occasion. It has a big impact because there are staff out in the field needing to VPN in to the office to update the main database.

To keep an eye on performance we added SNMP monitoring to the Centrastage console for that client, with an alert to trigger if it fell below 80%. The upload line speed is typically just under 1.2Mbps with the Annex M fast upload option we have on that line. It seems to fluctuate 5-10% in normal operation anyway - possibly some dodgy wiring or just being quite a way from the exchange.

The key element of SNMP monitoring is knowing what object identifier (OID) to monitor. We used snmpwalk to dump them all out to CSV. Then matched the known line speed values to the relevant OIDs:
 .1.3.6.1.2.1.2.2.1.5.4  --- ADSL download line speed
 .1.3.6.1.2.1.10.94.1.1.5.1.2.4  --- ADSL upload line speed

DrayTek have a list of some useful Vigor router OIDs

Have you got any other useful parameters or OIDs to monitor on a DrayTek router ?