Things to note regarding the Looking Glass are as follows ;
- There are 2 separate routers performing Looking Glass functions :
Domestic Looking Glass router includes BGP routes for Optus Customers , Optus
Internal , and National Peers only.
The International Looking Glass
router includes BGP routes for Optus Customers , Optus Internal , and
International Peers only
- Important BGP Communities configured by Optus include the following :
BGP Community 7474:1402 is used for Asian Routes
BGP Community 7474:1403 is used for US Routes
BGP Community 7474:1202 is used for NSW Customer Routes
BGP Community 7474:1203 is used for VIC Customer Routes
BGP Community 7474:1204 is used for QLD Customer Routes
BGP Community 7474:1205 is used for SA Customer Routes
BGP Community 7474:1206 is used for WA Customer Routes
Customers can also override BGP Local Preference in AS7474 by announcing the following BGP Communities with their routes -
BGP Community 7474:100 is used for Customer routes to set BGP Local Preference to 100 (the default Local Preference for customer routes)
BGP Community 7474:90 is used for Customer routes to set BGP Local Preference to 90
BGP Community 7474:80 is used for Customer routes to set BGP Local Preference to 80
BGP Community 7474:70 is used for Customer routes to set BGP Local Preference to 70
- These Routers do not have links into each Optus Router. They consist of
simply a Ethernet interface to plug it into the network. As such, ping's &
trace's will always take the same path. Ping's and trace's are only really
useful for verifying IP connectivity to a host, and do not demonstrate
accurately the path the packets will take from other routers in our network.
- RADB requests are done realtime by opening a port 43 connection to
whois.radb.net and are not results from a local cached database or similar.
- nslookup, dig and all other DNS resolution is done off a DNS resolver
at 220.127.116.11 where no domains are hosted (caching-only nameserver).