Routing for Verizon FIOS -- Reward for answer

Discussion in 'Cisco' started by Fletcher James, May 3, 2008.

  1. Fletcher James

    Merv Guest

    Do you need use of all 61 available address ?

    Becuase another option that one of the other responders proposed was
    to put part of the space on the outside interface and part on the

    like so

    int fa 0/0
    description inside LAN interface
    ip addr 70.x.x.98 ! default gateway

    int fa 0/1
    description outside interface facing Verizon FIOS ONT
    ip addr 70.x.x.66
    ip proxy-arp ! to answer ARP requests from 70.x.x.1

    ip classless
    ip route FastEthernet0/1 70.x.x.1

    You can use small block on outside and then add secondary address
    blocks to inside if you want to go to the bother
    Merv, May 6, 2008
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  2. Fletcher James

    Trendkill Guest

    Yes, except you would need to ensure Verizon adds a route (or turn up
    a protocol) to ensure that they know how to get back into the second
    half of your range. They would also need to turn up a secondary
    address, as .98/27 doesn't include .1 which is the gateway. You could
    turn up .68/30 with .69 as their secondary IP, .70 as your router, and
    then .96/27 on the inside interface. You'd lose .71-.95 unless you
    want to subinterface the router's connection back to the internal
    switch and trunk a /29, /28, and /27 instead. Although since Verizon
    doesn't seem to be able to do anything but transfer your calls, they
    probably won't turn up a secondary interface (even if its in your
    address range), and most likely will not add a static route for those
    subnets. May be worth a call though.....
    Trendkill, May 6, 2008
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  3. Fletcher James

    stephen Guest

    No - proxy ARP should take care of this is it is enabled on the cisco WAN

    The cisco will repond to ARP requests where it is the preferred route to the
    destination IP - in this case any IP addresses on the LAN side of the cisco.

    You can map further blocks on the LAN with static routes to the LAN side
    interface if the WAN side is only a small block such as a /30.

    ip route 70.x.x.80 FastEth 0/0 for example maps another 16

    They would also need to turn up a secondary
    Golden rule with a carrier who doesnt seem to have systems to do something,
    is not to ask for anything non standard (ie not standard for them).

    Even if you get it sorted and it works, can you get it to stay like that, or
    will someone "fix" it for you when they notice ?
    stephen, May 6, 2008
  4. Fletcher James

    Dan Lanciani Guest

    | Based on numerous tests, I have come to the conclusion that the
    | router/switch on Verizon's side is totally spoof protected: It will not
    | respond to an ARP query unless the source address is one of the 61 addresses
    | assigned to us

    You could always add a static arp entry for Verizon's gateway on your end
    and proceed with option D as I indicated. Of course, if they change their
    MAC address you will lose connectivity until you adapt.

    | (we've tried .2 and also tried assigning to the
    | outside of the router, and giving a static route to our gateway.) In one
    | case, .2 worked briefly -- probably because we had just swiched over, and it
    | had an association of our MAC address with a valid IP.

    Possibly there had been an incoming packet to which your router had
    responded as a proxy. That would not look spoofed since the address
    would be in your range, and in any case your router would have picked
    up the MAC address of Verizon's router in the process.

    Dan Lanciani
    [email protected]*com
    Dan Lanciani, May 6, 2008

  5. Would a sub interface help here at all? Say interface FastEthernet0/1.1

    I haven't read the whole thread yet, but that might help if you only
    wanted certain traffic using it?

    Charles N Wyble, Jun 3, 2008
  6. Fletcher James

    Trendkill Guest

    Trendkill, Jun 3, 2008
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