Cisco Cisco ASA 5510 Adaptive Security Appliance Leaflet

Cisco ASA Series 명령 참조 , S 명령

3장      show as-path-access-list through show auto-update 명령              

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Name: invalid-tcp-hdr-length

Invalid TCP Length:

    This counter is incremented when the security appliance receives a TCP packet whose 

size is smaller than minimum-allowed header length or does not conform to the received 

packet length.

Recommendation:

    The invalid packet could be a bogus packet being sent by an attacker.

Investigate the traffic from source in the following syslog.

Syslogs:

    500003.

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Name: invalid-udp-length

Invalid UDP Length:

    This counter is incremented when the security appliance receives a UDP packet whose 

size as calculated from the fields in header is different from the measured size of packet 

as received from the network.

Recommendation:

    The invalid packet could be a bogus packet being sent by an attacker.

Syslogs:

    None.

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Name: no-adjacency

No valid adjacency:

    This counter is incremented when the security appliance has tried to obtain an 

adjacency and could not obtain mac-address for next hop. The packet is dropped.

Recommendation:

    Configure a capture for this drop reason and check if a host with specified 

destination address exists on connected network or is routable from the device.

Syslogs:

   None.

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Name: unexpected-packet

Unexpected packet:

    This counter is incremented when the appliance in transparent mode receives a non-IP 

packet, destined to its MAC address, but there is no corresponding service running on the 

appliance to process the packet.

Recommendation:

    Verify if the appliance is under attack. If there are no suspicious packets, or the 

device is not in transparent mode, this counter is most likely being incremented due to a 

software error. Attempt to capture the traffic that is causing the counter to increment 

and contact the Cisco TAC.

Syslogs:

    None

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Name: no-route

No route to host: