06-14-2008
Making an internet connection from inside a local network to the outside world via a NAT creates a masqueraded connection. All of the packets outside look like the router IP, all of the packets inside the local network have different IP's. The NAT translates the IP addresses back and forth as packets come and go.
FIB is a table of forwarding addresses.
RFC 3222 (rfc3222) - Terminology for Forwarding Information Base (FIB) bas
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
I have 2 clustered hosts, is it possible for me to issue a netstat command against 1 host from the other ? (4 Replies)
Discussion started by: murphyboy
4 Replies
2. IP Networking
Hi
what is the command to see the process name/application name
along with the port number, connection status ...
netstat is not giving process/application name
Is there any way to know which application is holding which port?
Thanks in advance (3 Replies)
Discussion started by: axes
3 Replies
3. UNIX for Dummies Questions & Answers
hy guys,
I did netstat and it is listening, what can i do from the client side that to see if the port is open?
Regards
Charneet (1 Reply)
Discussion started by: charneet
1 Replies
4. Shell Programming and Scripting
Hi,
In my project we use sftp with batch mode (password less) script in parallel for 14 sessions which connects to 2 different servers alternatively i.e. 7 connects to one server say server1 and the other 7 connects to say server 2.
Now the problem is that these 14 sessions are run in... (5 Replies)
Discussion started by: dips_ag
5 Replies
5. UNIX for Dummies Questions & Answers
Do I have this command correct to show all current connections/sessions my Solaris box has? It does not seem to do anything.
netstat -an | grep EST (6 Replies)
Discussion started by: SIFT3R
6 Replies
6. Red Hat
Hi
Can any body tell me about TIME_WAIT status meaning in the following command output.
# netstat -anp|grep 5000
tcp 0 0 127.0.0.1:50006 0.0.0.0:* LISTEN 5058/ccsd
tcp 0 0 0.0.0.0:50008 0.0.0.0:* ... (3 Replies)
Discussion started by: mastansaheb
3 Replies
7. Shell Programming and Scripting
Hi All,
Need to run the netstat -i command on the list of hosts and check if "Ierrs" and "Oerrs" has value greaterthan 0.
for Ex: below output, driver bge1 and bge3 has Oerrs and Ierrs value > 0, So, script should report saying
"Netstat status for $host, driver bge1 has Oerrs = 20, Failed"... (5 Replies)
Discussion started by: Optimus81
5 Replies
8. Shell Programming and Scripting
Help required for creating a unix shell script using netstat command for retrieving total traffic in Kbytes with the source and destination address. (4 Replies)
Discussion started by: Samee
4 Replies
9. UNIX for Advanced & Expert Users
Hi All,
We have this regex:\\*.*?(.600).*?.(LISTEN|ESTABLISHED)
OS = Solaris 10
The purpose of this regex is to match the ports in output of "netstat -an" and report if any ports between 6000-6009 are getting used. The only problem is if I have something like this (sample output as... (6 Replies)
Discussion started by: sk2code
6 Replies
10. UNIX for Beginners Questions & Answers
Hi All,
I am trying to collect the listen ports info from netstat command in centos 7
From that info i am trying to collect all the foreign address IP for those ports.
I am using below script to do the same.
netstat -an |grep -w "LISTEN" |grep -v "127.0.0.1" |awk '{print $4}' >... (3 Replies)
Discussion started by: sravani25
3 Replies
NAT action in tc(8) Linux NAT action in tc(8)
NAME
nat - stateless native address translation action
SYNOPSIS
tc ... action nat DIRECTION OLD NEW
DIRECTION := { ingress | egress }
OLD := IPV4_ADDR_SPEC
NEW := IPV4_ADDR_SPEC
IPV4_ADDR_SPEC := { default | any | all | in_addr[/{prefix|netmask}]
DESCRIPTION
The nat action allows to perform NAT without the overhead of conntrack, which is desirable if the number of flows or addresses to perform
NAT on is large. This action is best used in combination with the u32 filter to allow for efficient lookups of a large number of stateless
NAT rules in constant time.
OPTIONS
ingress
Translate destination addresses, i.e. perform DNAT.
egress Translate source addresses, i.e. perform SNAT.
OLD Specifies addresses which should be translated.
NEW Specifies addresses which OLD should be translated into.
NOTES
The accepted address format in OLD and NEW is quite flexible. It may either consist of one of the keywords default, any or all, represent-
ing the all-zero IP address or a combination of IP address and netmask or prefix length separated by a slash (/) sign. In any case, the
mask (or prefix length) value of OLD is used for NEW as well so that a one-to-one mapping of addresses is assured.
Address translation is done using a combination of binary operations. First, the original (source or destination) address is matched
against the value of OLD. If the original address fits, the new address is created by taking the leading bits from NEW (defined by the
netmask of OLD) and taking the remaining bits from the original address.
There is rudimental support for upper layer protocols, namely TCP, UDP and ICMP. While for the first two only checksum recalculation is
performed, the action also takes care of embedded IP headers in ICMP packets by translating the respective address therein, too.
SEE ALSO
tc(8)
iproute2 12 Jan 2015 NAT action in tc(8)