debugging tcp

Function

The debugging tcp ipv6 packet command enables debugging of IPv6 TCP packets and outputs debugging information.

The undo debugging tcp ipv6 packet command disables debugging of IPv6 TCP packets.

The debugging tcp packet command enables debugging of TCP packets and outputs debugging information.

The undo debugging tcp packet command disables debugging of TCP packets.

By default, the debugging of TCP packets is disabled.

Format

debugging tcp packet [ src-ip src-address ] [ src-port src-port ] [ dest-ip dest-address ] [ dest-port dest-port ] [ socket-id socket-id ]

debugging tcp ipv6 packet [ src-ip src-address6 ] [ src-port src-port ] [ dest-ip dest-address6 ] [ dest-port dest-port ] [ socket-id socket-id ]

undo debugging tcp packet [ src-ip src-address ] [ src-port src-port ] [ dest-ip dest-address ] [ dest-port dest-port ] [ socket-id socket-id ]

undo debugging tcp ipv6 packet [ src-ip src-address6 ] [ src-port src-port ] [ dest-ip dest-address6 ] [ dest-port dest-port ] [ socket-id socket-id ]

Parameters

Parameter	Description	Value
src-ip src-address6	Displays packets of the specified source IPv6 address.	The address is a 32-digit hexadecimal number, in the format of X:X:X:X:X:X:X:X.
src-ip src-address	Displays packets of the specified source IPv4 address.	The value is in dotted decimal notation.
src-port src-port	Displays packets of the specified source TCP port number.	The value is an integer ranging from 0 to 65535.
dest-ip dest-address6	Displays packets of the specified destination IPv6 address.	The address is a 32-digit hexadecimal number, in the format of X:X:X:X:X:X:X:X.
dest-ip dest-address	Displays packets of the specified destination IPv4 address.	The value is in dotted decimal notation.
dest-port dest-port	Displays packets of the specified destination TCP port number.	The value is an integer ranging from 0 to 65535.
socket-id socket-id	Specifies the Socket ID.	The value is an integer ranging from 0 to 2147418111.

Views

User view

Default Level

3: Management level

Task Name and Operations

Task Name	Operations
ip-stack	debug

Usage Guidelines

Usage Scenario

The debugging tcp ipv6 command enables debugging of IPv6 TCP packets sent and received by the host and outputs debugging information. For example, to detect interworking between BGP 4+ connections, run the debugging tcp ipv6 command.

The debugging tcp event command enables debugging of TCP events and outputs debugging information so that you can detect the status of a TCP packet when the TCP packet is abnormal. For example, to detect change of TCP status change during establishment of a three-way handshake or closing of a four-way handshake, run the display tcp event command.

The debugging tcp command enables debugging of TCP packets and outputs debugging information about the TCP packets sent and received by the host. For example, to detect interworking between BGP connections and protocol interworking between MPLS LDP neighbors, run the debugging tcp command.

Example

# Enable debugging of TCP IPv6 packets, detect that the host sends a TCP IPv6 packet.

<HUAWEI> debugging tcp ipv6 packet
2037-11-24 22:10:15 RT5 %%01SOCKET/7/debug_tcp_packe(d):CID=2154103793;
TCP6 debug packet information:
420: Output: pid = 6620139, socketid = 7943,
(src =2001:db8:1::1 : 23, dst = 2001:db8:1::1 : 23973, 
seq = 2523083814, ack = 3434375926, datalen = 29, optlen = 20 ,
flag = ACK PUSH , window = 65526, ttl = 64, tos = 0)

# Enable debugging of TCP events, detect that the host initiates a three-way handshake and the TCP status changes from CLOSED to SYN_SENT.

<HUAWEI> debugging tcp event
Aug 25 2011 09:44:49 HUAWEI %%01SOCKET/7/debug_tcp_event(d):CID=0x80652795;
TCP state changed from [CLOSED] to [SYN_SENT]
(Time = 2011-8-25:9:44:49:684 ,Task name = XXXX ,Pid = 0x6503F6, Socket ID = 1)

# Enable debugging of TCP packets, detect that the host sends a TCP packet.

<HUAWEI> debugging tcp packet
2037-11-24 22:07:03 RT5 %%01SOCKET/7/debug_tcp_packe(d):CID=2154103793;
TCP debug packet information:
450: Output: pid = 6620139, socketid = 7925,
(src = 10.2.217.5:23, dst = 10.2.1.13:3356, seq = 1198729414, ack = 2793145850
, datalen = 42, optlen = 20 ,
flag = ACK PUSH , window = 65364, ttl = 64, tos = 192)

**Table 1** Description of the **debugging tcp** command output
Item	Description
pid	Path ID.
socketid	Socket ID.
dst	Destination IP address.
seq	Sequence numbers of ARP entries.
ack	Acknowledgment number.
datalen	Data length.
optlen	Option length.
flag	Flag bit.
window	Size of sliding window.
ttl	Time to live.
tos	Priority.
src	Source IP address.