CBF Networks Inc. dba Fastback Networks 105 User Manual
IBR Installation Guide
Page 20 of 38
Doc # 770-00023.1
Jan. 23, 2015
IBR automatically records the MAC address of a received packet, the port on which it was received, and
whether the packet has a VLAN designation. When an incoming packet arrives at IBR, the correct port and
whether the packet has a VLAN designation. When an incoming packet arrives at IBR, the correct port and
VLAN for delivery of the packet is determined by comparing the MAC address of the packet with the
corresponding entry in L2. If the MAC address is not in the L2 table, IBR will send the packet out to all ports
except the one on which it was received, and then record the port and VLAN of the device that responds to the
corresponding entry in L2. If the MAC address is not in the L2 table, IBR will send the packet out to all ports
except the one on which it was received, and then record the port and VLAN of the device that responds to the
packet.
When a MAC address in the L2 table has not been used within a preset time (the “aging time”), the MAC
address entry is automatically deleted from the table. The default aging time is three hundred (300) seconds.
Aging time is the only property of the L2 table functionality that can be changed. The L2 table can contain up
address entry is automatically deleted from the table. The default aging time is three hundred (300) seconds.
Aging time is the only property of the L2 table functionality that can be changed. The L2 table can contain up
to sixty-four thousand entries so that, with a reasonable aging time, there is little chance of an overflow
condition.
condition.
Using the CLI “show” command, an operator can display the contents of the L2 table.
5.2 Counters
Counters are implemented as two-dimensional arrays that associate traffic metrics with the corresponding
IBR ports (interfaces). Counters are activated by default and cannot be disabled; however, the contents of
IBR ports (interfaces). Counters are activated by default and cannot be disabled; however, the contents of
counters can be reset to zero or displayed by operator command. The counters in IBR are listed below
organized the way they would be displayed using the show command.
organized the way they would be displayed using the show command.
IBR102 # show interface counters
Shows a brief view, not including errors
IBR102 # show interface counters all
Shows all except TxQueue
IBR102 # show interface counters detail Shows the following counters
InBytes
Bytes received at a port
InUcastPkts
Unicast packets received at a port
InMcastPkts
Multicast packets received at a port
InBcastPkts
Broadcast packets received at a port
OutBytes
Bytes sent from a port
OutUcastPkts
Unicast packets sent from a port
OutMcastPkts
Multicast packets sent from a port
OutBcastPkts
Broadcast packets sent from a port
RxPause
Pause requests received
TxPause
Pause requests sent
IBR102 # show interface counters errors Shows error counters
CrcAlign-Err
Frames without an even # of octets or with CRC errors
Collisions
Collisions before successful transmission
Symbol-Err
Symbol errors
Undersize
Frames rcvd that are < 64 bytes
Oversize
Frames rcvd that are > 1514 bytes
Fragments
Oversized packets sent as fragments
Jabbers
Frames longer than 1518 octets
FCS-Err
Frames corrupted during transmission
Deferred-Xmit
Times xmsn delayed
Single-Col
Times only one collision occurred before successful xmsn
Multi-Col
Times multiple collisions occurred before successful xmsn
Late-Col
Collisions detected after > 512 bits sent
Excess-Col
Frames not sent due to excess # of retries
IBR102 # show interface counters txqueue Shows TxQueue counters
Octets
TX queue octets