TCP IP Illustrated

Default value is 150 75 seconds tcprecvspace the

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Unformatted text preview: for datagrams sent through the loop-back interface. If 0, this checksum is not calculated. nonlocsrcroute If 1 (default), received datagrams containing a source route option are forwarded. If 0, these datagrams are discarded. subnetsarelocal If 1 (default), a destination IP address with the same network ID as the sending host but a different subnet ID is considered local. If 0, only destination IP addresses on an attached subnet are considered local. This is summarized in Figure E.1. When sending to local destinations, TCP chooses the MSS based on the MTU of the outgoing interface. When sending to nonlocal destinations, TCP uses the default (536) as the MSS. tcp_keepidle Number of 500-ms clock ticks before sending a keepalive probe. Default value is 14400 (2 hours). tcp_keepintvl Number of 500-ms clock ticks between successive keepalive probes, when no response is received. Default value is 150 (75 seconds). tcp_recvspace The default size of the TCP receive buffer. This affects the window size that is offered. file:///D|/Documents%20and%20Settings/bigini/Doc...omenet2run/tcpip/tcp-ip-illustrated/append_e.htm (14 of 16) [12/09/2001 14.48.06] Appendix E: Configurable Options Default value is 16384. tcp_sendspace The default size of the TCP send buffer. Default value is 16384. tcp_ttl The default value for the TTL field for TCP segments. Default value is 60. udp_recvspace The default size of the UDP receive buffer. The default is 41600, allowing for 40 1024byte datagrams. udp_sendspace The default size of the UDP send buffer. Defines the maximum UDP datagram that can be sent. Default is 9216. udp_ttl The default value for the TTL field in UDP datagrams. Default value is 30. E.6 4.4BSD 4.4BSD is the first of the Berkeley releases to provide dynamic configuration for numerous kernel parameters. The sysctl(8) command is used. The names for the parameters were chosen to look like MIB names from SNMP. To examine a parameter we type: vangogh % sysctl net.inet.ip.forwarding net.inet.ip.forwarding = 1 To change a parameter we need superuser p...
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