For the requirement of service, some carrier applies to the out-interface of carrier B, in order to improve the speed of some dedicated users accessing some websites of carrier B, on NE40, re-direct these dedicated users' access service to the out-interface of carrier B.
PC－－S3026－－NE40（re-direct to eth2/0/7）－－the exterior network of carrier B
1.the dedicated user tests via NE40, the downloading speed is only about 20k, it is same with the downloading speed of the users underlying S3026.
2.detect the out interface of NE40 redirection and detect the out packets are massive while the in packets are small. Capture the packets and test, detect for the packet from the source address, they are sent out from the NE40 redirection, but the response packets are from another out interface.
3.recommend to switch the address of carrier A to the address of carrier B via NAT
For the packet sent by the re-direction, they are out from the out-interface (carrier B), but the corresponding packets are out from one out-interface (carrier A). The dedicated users use the addresses of carrier A, only the uplink device of carrier A has the backed routes, so though the packets are out from the carrier B, and backed from the carrier A, because the interconnecting bandwidth limitation of the dedicated user, the redirection is very slow.