LO(4) BSD Kernel Interfaces Manual LO(4)NAME
lo -- software loopback network interface
SYNOPSIS
device loop
DESCRIPTION
The loop interface is a software loopback mechanism which may be used for performance analysis, software testing, and/or local communication.
As with other network interfaces, the loopback interface must have network addresses assigned for each address family with which it is to be
used. These addresses may be set or changed with the SIOCSIFADDR ioctl(2). The loopback interface should be the last interface configured,
as protocols may use the order of configuration as an indication of priority. The loopback should never be configured first unless no hard-
ware interfaces exist.
If the transmit checksum offload capability flag is enabled on a loopback interface, checksums will not be generated by IP, UDP, or TCP for
packets sent on the interface.
If the receive checksum offload capability flag is enabled on a loopback interface, checksums will not be validated by IP, UDP, or TCP for
packets received on the interface.
By default, both receive and transmit checksum flags will be enabled, in order to avoid the overhead of checksumming for local communication
where data corruption is unlikely. If transmit checksum generation is disabled, then validation should also be disabled in order to avoid
packets being dropped due to invalid checksums.
DIAGNOSTICS
lo%d: can't handle af%d. The interface was handed a message with addresses formatted in an unsuitable address family; the packet was
dropped.
SEE ALSO inet(4), intro(4)HISTORY
The lo device appeared in 4.2BSD. The current checksum generation and validation avoidance policy appeared in FreeBSD 8.0.
BSD March 15, 2009 BSD
Check Out this Related Man Page
LO(4) BSD Kernel Interfaces Manual LO(4)NAME
lo -- software loopback network interface
SYNOPSIS
device loop
DESCRIPTION
The loop interface is a software loopback mechanism which may be used for performance analysis, software testing, and/or local communication.
As with other network interfaces, the loopback interface must have network addresses assigned for each address family with which it is to be
used. These addresses may be set or changed with the SIOCSIFADDR ioctl(2). The loopback interface should be the last interface configured,
as protocols may use the order of configuration as an indication of priority. The loopback should never be configured first unless no hard-
ware interfaces exist.
If the transmit checksum offload capability flag is enabled on a loopback interface, checksums will not be generated by IP, UDP, or TCP for
packets sent on the interface.
If the receive checksum offload capability flag is enabled on a loopback interface, checksums will not be validated by IP, UDP, or TCP for
packets received on the interface.
By default, both receive and transmit checksum flags will be enabled, in order to avoid the overhead of checksumming for local communication
where data corruption is unlikely. If transmit checksum generation is disabled, then validation should also be disabled in order to avoid
packets being dropped due to invalid checksums.
DIAGNOSTICS
lo%d: can't handle af%d. The interface was handed a message with addresses formatted in an unsuitable address family; the packet was
dropped.
SEE ALSO inet(4), intro(4)HISTORY
The lo device appeared in 4.2BSD. The current checksum generation and validation avoidance policy appeared in FreeBSD 8.0.
BSD March 15, 2009 BSD
I'm using ethereal to analyse my network from my pc.
There're too many TCP Bad checksum
1. between my PC and unix servers (checksum: 0x6660 )
2. between my PC and other servers (windows, novell) checksum: 0x6644 )
There're too many NBNS and BOOTP/DHCP Malformed Packet(Exception occured) ... (0 Replies)
Hi:
I´ve a problem in a 4.1.4.0 AIX server because is generating a loopback in its own ip address and this are consuming all the bandwidth.
I did many things trying to solve the problem but it doesn´t help.
1. Flush Routing tables
2. Get Up/Down Network interface
3. Add/remove Network... (0 Replies)
Hello,
I have just installed Solaris 9 x86 in a VMWare and the 1st problem I have is to enable the networking. I can only see the loopback interface and nothing else.
- I dont have any /etc/hostnames.xxx
- ifconfig -a shows only the loopback
- kstat -c net shows only the loopback ...
Any... (11 Replies)
hi everybody
Can you help me resolve flowwing two quetions?
First,i want to get every network information by using c/c++ function on Hpux OS.The network information include send packets,receive packets ,running status and so on .
Second,i want to get broadcast address by using c/c++... (0 Replies)
Hi Community,
Does anyone know how Disabling checksum offload on Solaris10?
Please help me, this issue is very urgent
Thank you
Have a nice day (3 Replies)
Hello everybody,
I'm reading and learning a lot about TCP/IP protocols, and i want to know how to calculate the IP header checksum manually. I've searched for it EVERYWHERE! and none of options work.
I've read a function that does it pretty good, but i can't "translate" it into a human form so... (3 Replies)
Hi,
could any one tell is there any test-suite or any idea How to do data corruption validation testing, means there is no any data corruption ?
Regards
Manish (1 Reply)
Hi,
I have installed Solaris 10 on VMware7, When i used ifconfig -a to check network interface, it has shown lo0 as loopback interface.
Please advise how to configure network interfaces using VMware. (1 Reply)
This code works perfect when using a machine with only one interface online. (Excluding the loopback of course) But when I have other interface up for vmware or a vpn the output gets mixed up. I know I had this working when I was just reading ip's from files so I know it is not a problem with... (8 Replies)
hello All,
I am not heavily conversant with *nix, so few of you may find the question to be naive.
Question : Will *nix Kernel process packets not originating from a loopback interface, but received on a loopback interface?
Scenario:
I have an application running which can strip packets... (2 Replies)