FEET let to thIIhOI oIOIQ EoFIE the.to let to EIIeo - PDF document

Flooding on recv(pkt, ifin): 1h37 µ for i in interfaces: if i != ifin: 2 send(pkt, i) I Too 2 0 TOLE If Deliver Packets Bat HI The Cycles Bad Packet Destinationitf FEET

let to thIIhOI oIOIQ EoFIE the.to let to EIIeo eo.to.EE EEEIIf 2Oa thIIIo oFI

t 1 f O Io.to IEEII.fEo.yo E lhOI b 3 HhI t E E e i In F iI EEE 0 everywhere all the time Packets

How to solve o Remember all packets forwarded should be remembered How many packets How much memory Change graph so there are no cycles How to change graphs Remove links so that no cycles remain 4 Without Disconnecting Graph l

Example HI IIo The to 1h37 THI YO MY FOLK

Q How to remove links Assume all networks are designed tobe.org It Done by someone else Does not work in many environments

Automate Modifiedflood deactivated = Set() on recv(pkt, ifin): if ifin in deactivated: return for i in interfaces: if if (i !=ifin and O i not in deactivated): send(pkt, i) deactivated'ER Deactivated

Algorithm that converts graph witch codes to acyclic graph ME 4 tlDO OB Oc Ffh fr Requirements khI A Acyclic 0 Ehf Do 03 Spanning Root trEPEoIninsEEe ro.to EioFII How

Algorithm Root o R id roofdist IT oEEII.ainoz eo.to t I h r da.A IIko cnn.ioa.IE Ai 1 see 7 I

From Algorithm to Protocol StepI Root = id On boot: Bcast((root=root) On recv(p, i): If p.root < root: Root = p.root Identity Root Bcast((root = root) 43 A BFS Step 2

Putting it all together is ri