diff options
Diffstat (limited to 'Documentation/networking/ip-sysctl.txt')
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 26 |
1 files changed, 8 insertions, 18 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index a46d78583ae1..8a984e994e61 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -16,8 +16,12 @@ ip_default_ttl - INTEGER Default: 64 (as recommended by RFC1700) ip_no_pmtu_disc - BOOLEAN - Disable Path MTU Discovery. - default FALSE + Disable Path MTU Discovery. If enabled and a + fragmentation-required ICMP is received, the PMTU to this + destination will be set to min_pmtu (see below). You will need + to raise min_pmtu to the smallest interface MTU on your system + manually if you want to avoid locally generated fragments. + Default: FALSE min_pmtu - INTEGER default 552 - minimum discovered Path MTU @@ -267,17 +271,6 @@ tcp_max_orphans - INTEGER more aggressively. Let me to remind again: each orphan eats up to ~64K of unswappable memory. -tcp_max_ssthresh - INTEGER - Limited Slow-Start for TCP with large congestion windows (cwnd) defined in - RFC3742. Limited slow-start is a mechanism to limit growth of the cwnd - on the region where cwnd is larger than tcp_max_ssthresh. TCP increases cwnd - by at most tcp_max_ssthresh segments, and by at least tcp_max_ssthresh/2 - segments per RTT when the cwnd is above tcp_max_ssthresh. - If TCP connection increased cwnd to thousands (or tens of thousands) segments, - and thousands of packets were being dropped during slow-start, you can set - tcp_max_ssthresh to improve performance for new TCP connection. - Default: 0 (off) - tcp_max_syn_backlog - INTEGER Maximal number of remembered connection requests, which have not received an acknowledgment from connecting client. @@ -451,7 +444,7 @@ tcp_fastopen - INTEGER connect() to perform a TCP handshake automatically. The values (bitmap) are - 1: Enables sending data in the opening SYN on the client. + 1: Enables sending data in the opening SYN on the client w/ MSG_FASTOPEN. 2: Enables TCP Fast Open on the server side, i.e., allowing data in a SYN packet to be accepted and passed to the application before 3-way hand shake finishes. @@ -464,7 +457,7 @@ tcp_fastopen - INTEGER different ways of setting max_qlen without the TCP_FASTOPEN socket option. - Default: 0 + Default: 1 Note that the client & server side Fast Open flags (1 and 2 respectively) must be also enabled before the rest of flags can take @@ -588,9 +581,6 @@ tcp_limit_output_bytes - INTEGER typical pfifo_fast qdiscs. tcp_limit_output_bytes limits the number of bytes on qdisc or device to reduce artificial RTT/cwnd and reduce bufferbloat. - Note: For GSO/TSO enabled flows, we try to have at least two - packets in flight. Reducing tcp_limit_output_bytes might also - reduce the size of individual GSO packet (64KB being the max) Default: 131072 tcp_challenge_ack_limit - INTEGER |