Setting Tcp Timers; Enabling Sending Icmp Error Messages - HPE FlexNetwork HSR6800 Configuration Manual

Step
2. Set the size of TCP receive/send
buffer.

Setting TCP timers

You can set the following TCP timers:
•
SYN wait timer—TCP starts the SYN wait timer after sending a SYN packet. Within the SYN
wait timer if no response is received or the upper limit on TCP connection tries is reached, TCP
fails to establish the connection.
•
FIN wait timer—TCP starts the FIN wait timer when TCP changes the connection state to
FIN_WAIT_2. If no FIN packet is received within the timer interval, TCP terminates the
connection. If a FIN packet is received, TCP changes the connection state to TIME_WAIT. If a
non-FIN packet is received, TCP restarts the timer, and tears down the connection when the
timer expires.
To set TCP timers:
Step
1. Enter system view.
2. Set TCP timers.

Enabling sending ICMP error messages

Perform this task to enable sending ICMP error messages, including redirect, time exceeded, and
destination unreachable messages.
•
ICMP redirect messages
A host that has only one default route sends all packets to the default gateway. The default
gateway sends an ICMP redirect message to inform the host of a correct next hop by following
these rules:
The receiving and sending interfaces are the same.
The selected route is not created or modified by any ICMP redirect messages.
The selected route is not destined for 0.0.0.0.
There is no source route option in the received packet.
ICMP redirect messages simplify host management and enable hosts to gradually optimize
their routing table.
•
ICMP time exceeded messages
A device sends ICMP time exceeded messages by following these rules:
The device sends the source an ICMP TTL exceeded in transit message when the following
conditions are met:
− The received packet is not destined for the device.
− The TTL field of the packet is 1.
Command
tcp window
window-size
Command
system-view
•
Set the TCP SYN wait timer:
tcp timer syn-timeout time-value
•
Set the TCP FIN wait timer:
tcp timer fin-timeout time-value
189
Remarks
The default buffer size is 63 KB.
Remarks
N/A
By default:
•
The TCP SYN wait timer is 75
seconds.
•
The TCP FIN wait timer is
675 seconds.