This means that the interface specified in the message has a packet counter that has decreased in number.
This condition can occur if a packet is
counted and then dropped. This event was detected and corrected.
BACKWARD counters message means/indicates that the RSP detected a negative count with time. i.e. with time, interface counter values on the VIP interfaces are monitored/updated by RSP and RSP expects these counts to be positive and increasing; however when it gets two count values A and B at times t0 and t1 respectively (where t0 is less than t1), it computes the difference B minus A and when it seees this
difference as negative, it prints the following message and corrects the
negative count.
This could be a normal message when a link is indeed loaded.
However, a bug has been filed regarding seeing this error message observed on multilink interfaces.
CSCef68698
%IF-4-BACKWARD_COUNTERS: Corrected for backward rx_bytes counters
In summary, the error message is related to counter so it would not affect the operation
of the network.