diff options
Diffstat (limited to 'Documentation/networking/ip-sysctl.txt')
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 56 |
1 files changed, 39 insertions, 17 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index c7fc1072494..dd52d516cb8 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -30,16 +30,24 @@ neigh/default/gc_thresh3 - INTEGER Maximum number of neighbor entries allowed. Increase this when using large numbers of interfaces and when communicating with large numbers of directly-connected peers. + Default: 1024 neigh/default/unres_qlen_bytes - INTEGER The maximum number of bytes which may be used by packets queued for each unresolved address by other network layers. (added in linux 3.3) + Seting negative value is meaningless and will retrun error. + Default: 65536 Bytes(64KB) neigh/default/unres_qlen - INTEGER The maximum number of packets which may be queued for each unresolved address by other network layers. (deprecated in linux 3.3) : use unres_qlen_bytes instead. + Prior to linux 3.3, the default value is 3 which may cause + unexpected packet loss. The current default value is calculated + according to default value of unres_qlen_bytes and true size of + packet. + Default: 31 mtu_expires - INTEGER Time, in seconds, that cached PMTU information is kept. @@ -199,15 +207,16 @@ tcp_early_retrans - INTEGER Default: 2 tcp_ecn - INTEGER - Enable Explicit Congestion Notification (ECN) in TCP. ECN is only - used when both ends of the TCP flow support it. It is useful to - avoid losses due to congestion (when the bottleneck router supports - ECN). + Control use of Explicit Congestion Notification (ECN) by TCP. + ECN is used only when both ends of the TCP connection indicate + support for it. This feature is useful in avoiding losses due + to congestion by allowing supporting routers to signal + congestion before having to drop packets. Possible values are: - 0 disable ECN - 1 ECN enabled - 2 Only server-side ECN enabled. If the other end does - not support ECN, behavior is like with ECN disabled. + 0 Disable ECN. Neither initiate nor accept ECN. + 1 Always request ECN on outgoing connection attempts. + 2 Enable ECN when requested by incomming connections + but do not request ECN on outgoing connections. Default: 2 tcp_fack - BOOLEAN @@ -215,15 +224,14 @@ tcp_fack - BOOLEAN The value is not used, if tcp_sack is not enabled. tcp_fin_timeout - INTEGER - Time to hold socket in state FIN-WAIT-2, if it was closed - by our side. Peer can be broken and never close its side, - or even died unexpectedly. Default value is 60sec. - Usual value used in 2.2 was 180 seconds, you may restore - it, but remember that if your machine is even underloaded WEB server, - you risk to overflow memory with kilotons of dead sockets, - FIN-WAIT-2 sockets are less dangerous than FIN-WAIT-1, - because they eat maximum 1.5K of memory, but they tend - to live longer. Cf. tcp_max_orphans. + The length of time an orphaned (no longer referenced by any + application) connection will remain in the FIN_WAIT_2 state + before it is aborted at the local end. While a perfectly + valid "receive only" state for an un-orphaned connection, an + orphaned connection in FIN_WAIT_2 state could otherwise wait + forever for the remote to close its end of the connection. + Cf. tcp_max_orphans + Default: 60 seconds tcp_frto - INTEGER Enables Forward RTO-Recovery (F-RTO) defined in RFC4138. @@ -1514,6 +1522,20 @@ cookie_preserve_enable - BOOLEAN Default: 1 +cookie_hmac_alg - STRING + Select the hmac algorithm used when generating the cookie value sent by + a listening sctp socket to a connecting client in the INIT-ACK chunk. + Valid values are: + * md5 + * sha1 + * none + Ability to assign md5 or sha1 as the selected alg is predicated on the + configuarion of those algorithms at build time (CONFIG_CRYPTO_MD5 and + CONFIG_CRYPTO_SHA1). + + Default: Dependent on configuration. MD5 if available, else SHA1 if + available, else none. + rcvbuf_policy - INTEGER Determines if the receive buffer is attributed to the socket or to association. SCTP supports the capability to create multiple |