metrotek ETS-1000L, Руководство по эксплуатации

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16 Loopback
1 2 4
5
1 2 4
5
MAC Dst MAC Src
IP Src
IP Dst
MAC Dst
MAC Src IP Src IP Dst
Figure 5.2. Loopback at the data link layer
Note:
if a frames destination MAC address is not equal to the MAC
address of
ETS-1000L
, 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 and destination IP address are equal to the MAC and
IP address of
ETS-1000L .
1 2 4
5
1 2 4 5
MAC Dst MAC Src
IP Src
IP Dst
MAC Dst MAC Src
IP Src
IP Dst
Figure 5.3. 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.
ETS-1000L. Operating manual