Knowledge base PPPoE services
The Ethernet service where we provide Internet access can work in one of two ways.
Routed block /29
This is perhaps the more traditional way to provide service. We operate an Ethernet link that has 8 IPv4 addresses (6 usable), where 3 are for us and 3 are for you. We operate VRRP over two routers, so one IPv4 is quoted as your gateway address.
We will route traffic for any additional blocks to you on your gateway address (with the extra 2 IPv4 addresses typically for VRRP your side).
For fallback operation we constantly monitor the gateway address you have given us at an ARP level, and only announce your IP addresses internally as long as that address is answering ARPs. This ensures our two routers correctly announce themselves in the event of a partial link failure. It is therefore important to maintain your gateway device on the link.
For IPv6 we also do VRRP and provide a gateway and router announcements.
The other way we can operate is to provide a PPPoE endpoint with a suitable username and password. This can then allow high speed LCP echo based fallback.
We route IPv4 and IPv6 via the PPP link. For redundancy we provide two separate PPPoE endpoints on the Ethernet link.
PPPoE can often be useful for a much faster fallback than ARP based detection, and you can use the same credentials on ADSL and mobile backup links.
It is normally the case to use PPPoE on any FTTC based links as the PPPoE packets get additional data on the actual link speed automatically. This ensures better operation of shaping for VoIP, etc.