SNMP and HA to get external ip address

Configuration
1

I have a router that supports SNMP and I currently get the uptime with this code:

- platform: snmp
  name: 'DDWRT1 Uptime'
  host: 192.168.1.1
  community: xxx
  baseoid: 1.3.6.1.2.1.25.1.1.0
  accept_errors: true
  unit_of_measurement: 'days'
  value_template: '{{((value | int) / 8640000) | round(1)}}'
  scan_interval: 60

I am trying to use the following to get my external IP address and post it to a tab on the front end. I have use iReasonings MIB browser to verify that the IP address is the response and that it is just a normal format. When I ask with the following code, I get 3 garbage characters on the tab display.

- platform: snmp
  name: 'DDWRT external'
  host: 192.168.1.1
  community: xxx
  baseoid: .1.3.6.1.2.1.4.21.1.7.0.0.0.0
  value_template: '{{ value }}'
  scan_interval: 60

  data_sets:
    name: Other data sets
    icon: mdi:router-wireless
    view: no
    entities:
      - sensor.ddwrt1_uptime
      - sensor.ddwrt_external

The output on screen whith the above display is b followed by an a with 2 dots above it and an 8.

Any idea what I am doing wrong?

Forgot to mention, running the lastest Hass.io update on an RPi2.

2

I don’t know much about SNMP but the baseoid in your working example starts with ‘1’ and in the non working starts with ‘.’