VLSM Routing

MaxRobinsonMaxRobinson Member Posts: 2 ■□□□□□□□□□
I'm attempting to configure my first network using subnets but I'm struggling to setup the IPs for a link between two routers.
When I was designing my addressing, I assigned /30 to one port and /30 for the other, however when I try to assign this on the router with 'ip address' it tells me it is a bad mask yet I've seen others use similar IPs.
So my question would be can anyone point me towards the issue with this ip and mask for this serial link?
I can also provide the addressing table I created if it would be of use.
Thanks so much, learning networking feels extremely complicated


  • Options
    bhiter010bhiter010 Member Posts: 6 ■■□□□□□□□□
    you have /30 to one port and /30 for the other
    router's ip (mask 22!)
    if you place new ip's in your subnet, you should use the same mask 22 in your case! (or /30)
    try ip calculator it is very useful for understanding networks

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    volfkhatvolfkhat Member Posts: 1,049 ■■■■■■■■□□
    a /30 subnet means that the "usable" ip range is:

    .1 & .2
    .5 & .6
    .9 & .10
    .13 & .14
    .125 & .126
    .129 & .130
    .133 & .134
    and so forth

    If you don't really understand how this works... then you shouldn't bother trying to work on network gear.

    Learn the "MAGIC number" technique:

    then you'll be good to go!
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