metrotek Bercut-ETL, Руководство по эксплуатации

Страница: 16 / 25

16 Loopback
Figure 4.2. Loopback at the data link layer
Note:
if a frames destination MAC address is not equal to the MAC
address of
Bercut-ETL
, the frame will not be retransmitted.
Note:
frames with equal destination and source MAC address are not
retransmitted at the data link, network and transport layers.
•
At the Network layer (L3) the incoming traffic (without error packets)
is being retransmitted backward with source and destination IP and MAC
addresses swapping.
Note:
the frame will be retransmitted only if a frames destination
MAC address is equal to the MAC address of
Bercut-ETL
.
Figure 4.3. Loopback at the network layer
•
At the Transport layer (L4) the incoming traffic (without error pack-
ets) is being retransmitted backward with source and destination IP and
MAC addresses swapping and source and destination TCP/UDP addresses
swapping.
Note:
the frame will be retransmitted only if a frames destination
MAC address is equal to the MAC address of
Bercut-ETL
.
Bercut-ETL. Operating manual