Changes between Version 44 and Version 45 of GENIExperimenter/Tutorials/ClickExample/Execute


Ignore:
Timestamp:
07/16/14 14:36:55 (5 years ago)
Author:
sedwards@bbn.com
Comment:

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  • GENIExperimenter/Tutorials/ClickExample/Execute

    v44 v45  
    224224===  Packet transformation ===
    225225
    226   i. The more interesting configuration appears here, in the '''top.click''' configuration file. In a local terminal type:
    227   {{{
     226  i. The more interesting configuration appears in the '''top.click''' configuration file.
     227
     228{{{
     229#!div style="background: #ffd; border: 3px ridge; width: 685px;"
     230
     231In a local terminal type:
     232{{{
    228233ssh -A top "cat top.click"
    229234}}}
    230   The output will look like :
     235The output will look like :
    231236  {{{
    232237#!cpp
     
    266271FromDevice(eth4) ->  Classifier(12/7744) -> Print(inR) -> restore;
    267272}}}
    268 
     273}}}
    269274  As indicated in the comments, the top portion of the configuration listens ('''!FromDevice''') for IP packets arriving on the interface connected to '''hostA''' (that's '''eth3''' in this example). It then creates a new 16-byte field at the head of the packet (two bytes added by the '''Unstrip''' operation, plus the existing 14-byte Ethernet header. It fills that field with what could be important routing instructions, but in this case is just graffiti ('''!StoreData'''). The '''route''' operation then routes the packet via either the '''left''' or '''right''' router toward '''hostB'''. In either case, it wraps the packet in a fresh Ethernet header ('''!EtherEncap''') with a distinctive ether type code (0x7744), logs the new packet on its way out ('''Print''') and sends it out on the correct interface ('''!ToDevice''').
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