Dell Force10 E300, Configuration Manual

Page: 577 / 1262

Layer 2 | 577
Far-end Failure Detection
Far-end Failure Detection is supported only on platform:
e
Far-end Failure Detection (FEFD) is a protocol that senses remote data link errors in a network. It responds
by sending a unidirectional report that triggers an echoed response after a specified time interval.
Figure 25-10. Configuring Far-end Failure Detection
The report consists of several packets in SNAP format that are sent to the nearest known MAC address.
In the event of a far-end failure, the device stops receiving frames, and after the specified time interval
assumes that the far-end is not available. The connecting line protocol is brought down so that upper layer
protocols can detect the neighbor unavailability faster.
FEFD state changes
FEFD enabled systems (comprised of one or more interfaces) will automatically switch between four
different modes: Idle, Unknown, Bi-directional, and Err-disabled.
1. An interface on which FEFD is not configured is in Idle state.
2. Once FEFD is enabled on an interface, it transitions to the Unknown state, and sends an FEFD packet
to the remote end of the link.
3. When the local interface receives the echoed packet from the remote end, the local interface transitions
to the Bi-directional state.
4. If the FEFD enabled system is configured to use FEFD in Normal mode and neighboring echoes are
not received after three intervals, (each interval can be set between 3 and 300 seconds by the user) the
state changes to unknown.
Force10(conf-if-gi-4/0)#show config
!
interface GigabitEthernet 4/0
no ip address
switchport
fefd
no shutdown
Force10(conf-if-gi-1/0)#show config
!
interface GigabitEthernet 1/0
no ip address
switchport
fefd
no shutdown
R1
R2
2w0d4h : FEFD packet sent via interface Gi 1/0
Sender state -- Bi-directional
Sender info -- Mgmt Mac(00:01:e8:14:89:25), Slot-Port(Gi 1/0)
Peer info -- Mgmt Mac (00:01:e8:14:89:25), Slot-Port(Gi 4/0)
Sender hold time -- 3 (second)
R1
R2
2w0d4h : FEFD packet sent via interface Gi 4/0
Sender state -- Bi-directional
Sender info -- Mgmt Mac(00:01:e8:14:89:25), Slot-Port(Gi 4/0)
Peer info -- Mgmt Mac (00:01:e8:14:89:25), Slot-Port(Gi 1/0)
Sender hold time -- 3 (second)
Keep-alive
Echo
Interval
Layer2 001