Lexmark IBM 9077 - Manual (Page 212)

194 IBM 9077 SP Switch Router: Get Connected to the SP Switch
On node 1 in SP2, ping the SP Switch interfaces of the chosen nodes in
SP21, for example:
If these ping commands fail, check routing settings again. If everything is
as it should be, try to ping the SP Switch Router Adapter cards and check
the HIPPI connection to find the failing part.
If any further errors occur, check cabling, the configuration of SP Switch
Router media cards (See Section 3.7, “Step-by-Step Media Card
Configuration” on page 86 and Section 5.2.1, “Configuration of a Dual SP
Switch Router Connection” on page 187) and also the network adapters in
the nodes.
5.2.2.1 How the Traffic Flows
Why is it possible to ping 192.168.14.129, netmask 255.255.255.128 from
node 6 in SP21 with IP address 192.168.14.6, netmask 255.255.255.0?
This question arose in Section 5.2.1, “Configuration of a Dual SP Switch
Router Connection” on page 187. We treat this problem in a more general
manner and look at our complex configuration (Figure 60 on page 190). What
happens when our three chosen nodes in SP21
ping node 1 in SP2? The next
three figures take a close look at the IP traffic flow. All three figures contain a
simplified illustration of our complex configuration (Figure 60 on page 190).
Figure 61 on page 195 shows the IP traffic flow when issuing the
ping
192.168.13.1 on node 6 in SP21. All packets are first forwarded to the SP
Switch Adapter card with IP address 192.168.14.4, according to the routing
settings. From this SP Switch Adapter card all packets are forwarded via
HIPPI connection to the only SP Switch Adapter card in GRF 400, which
forwards the traffic to node 1 in SP2. The way back follows the same route.
The SP Switch Adapter card with IP address 192.168.14.4 has no problem
delivering IP packets to node 6 in the same subnet.
root@sp2n01:/ ping 192.168.14.6
PING 192.168.14.6: (192.168.14.6): 56 data bytes
64 bytes from 192.168.14.6: icmp_seq=0 ttl=253 time=1 ms
64 bytes from 192.168.14.6: icmp_seq=1 ttl=253 time=1 ms
^C
----192.168.14.6 PING Statistics----
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 1/1/1 ms