Hitachi GR2000 Series Installation Manual page 263

the defined VC bandwidth is exceeded, GR2000 discards the excessive amount o
cells as illustrated in Figure 4-10. At this process called shaping, possible loss of l
with the other device may result if a dynamic routing protocol such as RIP or OS
has been used on the subject interface. The reason is because the shaping proce
discards packets regardless of the packet type, thus possibly discarding the cont
packet of the routing protocol. Shown below is an example of RIP being used as t
routing protocol.
When 3 minutes or more have passed since the last transmission of the RIP
control packet to the other device, the route information taking route on the
subject interface is deleted from the routing table of that device, causing link
disconnection with that device.
Reconstruction of the routing table and recovery of the link will take a maxim
of 30 seconds since the shaping process on the own router terminates.
In order to avoid the above-mentioned problem, it is recommended to plan the VC
bandwidth to withstand a possible rise in traffic.
Own router