Multicast Address-Set Claim (MASC) Stable Storage P a vlin - PDF document

Multicast Address-Set Claim (MASC) Stable Storage P a vlin Radosla v o v (USC/ISI)

USC F OIL 1 MASC T ypical En vironmen t MASC will b e t ypically run on BG(M)P � routers The routers ma y not ha v e stable storage �

USC F OIL 2 Ho w do es a MASC no de restore its state after a reb o ot? All state is in the net w ork : MASC p eers exc hange all appropriate PRE- FIX IN USE, CLAIMs, etc after connection (re)establishmen t. If all (diskless) MASC no des within an AS re- b o ot at once, the MASC AS still can restore its state from external (paren ts, c hildren, siblings) MASC ASs, but... ...Y ou Ha v e to T rust Y our Neigh b ors Ab out Y our In ternal State

USC F OIL 3 Solution 1: T rust them! Simple �

USC F OIL 4 Solution 2: Use AAP to store in ternal state to diskfull MADCAP serv ers More complicated MASC-AAP-MADCAP � en vironmen t Can record only lo cal domain PREFIX IN USE � and the allo cated b y MADCAP addresses

USC F OIL 5 Solution 3: Run at least one diskfull MASC no de (non-router) Can trust it for all states � W orks for MASC leaf domains � AAP is not used an ymore to sa v e/retriev e � lo cal domain PREFIX IN USE, but only to rep ort allo cated b y MADCAP addresses But...

USC F OIL 6 Con�guration \Problem" The MASC p eering con�guration of the � BG(M)P/MASC routers is implicit Adding non-router MASC no de to the MASC � mesh is explicit

USC F OIL 7 Con�guration \Problem" Solution 1. Diskfull MASC no de m ulticasts MASC OPEN messages (UDP) 2. If a Diskless MASC no de reb o ots and needs to restore its state, it starts listening for these messages, and obtains the Diskfull MASC no de address 3. The Diskless MASC no de then uses normal MASC handshaking to initiate MASC p eer- ing to the Diskfull MASC 4. After Diskless MASC no de state is \up to date", connection can b e closed