Re: Ping/FTP to active IP address

[Scott Klement <klemscot@xxxxxxxxxxxx>]

>
>       Yes , the ping was in quotes , Yes I can ping the local host , all
> my other IP routes are fine and I can ping these.
>

All other ROUTES are fine?  I don't understand what you mean by this.
Do you have a lot of different gateways/routers?

>
> Sorry , I did mean to say that the IP address was added to the
> routing table (ADDTCPRRTE) rather than the Host table , My mistake.
>
> Route            Subnet    Next           Route
> Destination      Mask      Hop          Available
> 172.30.128.10    *HOST  172.30.195.243     *YES
>
> The next hop being my default gateway
> With the binding interface set as my AS400 address.
>
> I do have an entry for a default route
>
> *DFTROUTE        *NONE  172.30.195.243     *YES


Why have two routes like this?

    If destination=172.30.128.10 then
        gateway=172.30.195.243
    else
        gateway=172.30.195.243

Why be redundant?
What good does it do you to have a separate route just for this host?

>
> Could there be a firewall which is allowing some IPs to do the ping, and
> some not to?
>
>       Reply from my Comms guy,
>       At no time do you go near the firewall. There are no filters or
> restrictions on this link. If a device can get to Dublin from Swindon with
> the same default gateway as the AS400 then any device will be able to get to
> Dublin as the routers are not device specific.
>

Well, here's what puzzles me:  You say the remote host can telnet to your
AS/400 and get a signon screen.   This requires packets to be sent both
ways -- both from the remote host to your AS/400, and from your AS/400 to
the remote host.

So, I'm asking myself, "What makes those packets different from the
packets in your PING?"   The only obvious difference is which host
originated the conversation.   Normally, only firewalls dig deep enough
into the packet to determine which packets are the origin of a
conversation, and which are just packets in the middle of a conversation.

Obviously, if a PC works and the AS/400 does not, and they're on the same
network segment, the problem will be whatever is different between them.

So, what is different?   If you list the routes on the PC and the routes
on the AS/400, what are the differences?    Are the TTLs on the packets
an issue?  Is MTU or MSS different?

Compare them, find the differences.   That's my advice, for now.