Similar to a http://whatismyip.com lookup. It would obviously need to query a computer out there. Just wondering if anyone had a clever way to do it?
1
-
See also unix.stackexchange.com/a/81699/37512.– Timo TijhofJul 4, 2013 at 2:57
Add a comment
|
12 Answers
curl http://myip.dnsomatic.com
dig +short myip.opendns.com
This only works if you are using OpenDNS as your dns server.
If you aren't, one of these should work:
dig +short myip.opendns.com @208.67.222.222 dig +short myip.opendns.com @208.67.220.220 dig +short myip.opendns.com @208.67.222.222 @208.67.220.220
answered Jul 17, 2009 at 3:33
-
1
-
-
-
+1 for using DNS to find out an IP (instead of http). You could also specify the dns server using its name e.g.,
@resolver1.opendns.com(for readability)– jfsFeb 27, 2014 at 14:38
STUN is the proper solution.
% stun -v stun.ekiga.net ... MappedAddress = 88.189.152.187:18009
- a list of public STUN servers
- a free software STUN client
- The STUN standard
answered Jul 20, 2009 at 17:39
You can use curl to get the page from something like whatismyip and then get the pieces out. I used whatismyipaddress.com in this example...obviously the fields will differ with different services.
curl -s http://whatismyipaddress.com/ | grep LOOKUPADDRESS | awk '{ print $4 }'
lynx -dump http://www.pcmesh.com/ip-check.cgi | awk '/REMOTE_ADDR/{print $2}'
One must use OpenDNS' servers to use this... You can query a certain DNS server with dig like that:
dig +short myip.opendns.com @208.67.222.222
the simplest way is: curl ifconfig.me
i just run a traceroute to somewhere on the internet and look for the hop out of our local network.
perhaps there's a better way?
answered Jul 17, 2009 at 0:52
"lynx http://whatismyip.com"
I love to use curl -4 icanhazip.com. The service is made to be used in scripts.
you can use the ifconfig command to list all interfaces and their associated IP address(es).
so, if you know your internet interface is ppp0, you can run
$ ifconfig ppp0
ppp0 Link encap:Point-to-Point Protocol
inet addr:X.X.XX.X P-t-P:Y.Y.Y.Y Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1444 Metric:1
RX packets:198986 errors:0 dropped:0 overruns:0 frame:0
TX packets:122929 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:134195571 (127.9 MiB) TX bytes:17101701 (16.3 MiB)
X.X.X.X will be your IP address. Y.Y.Y.Y is the IP address of the next hop.
you can then postprocess the output of ifconfig with grep/awk/sed/cut/perl/whatever to extract just the IP.
another alternative, if you have the iproute tools installed, is to use the ip command. e.g.
$ ip addr list ppp0
21842: ppp0: mtu 1444 qdisc htb state UNKNOWN qlen 3
link/ppp
inet X.X.X.X peer Y.Y.Y.Y/32 scope global ppp0
that's probably easier to read and certainly easier to parse:
$ ip addr list ppp0 | awk '/inet/ {print $2}'
X.X.X.X
-
- There is chance that any IP in ifconfig will not match real Internet IP (in case of biNAT) - In FreeBSD there is no iproute2 package, so ip command is not applicable Jul 18, 2009 at 3:57
-
true, i don't use NAT so it never occurred to me to....it just seemed "wrong" to me to use an external service for information you can query your own system about. even with NAT, i'd still prefer to figure out how to query the router doing the NAT (perhaps via an SNMP query) than to rely on an external service which may or may not be available when i need it.– casJul 18, 2009 at 4:44
-
@Craig, Your approach is fine. However, its not an external IP unless you can reach it on that value from outside. You do have to rely on an external point for this answer. The idea is to find a reliable (at least more than your perimeter point) external point for the query. OpenDNS is a good point.– nikJul 19, 2009 at 17:17
-
@nik: the only likely case where your border router's IP isn't the external IP is when you're behind multiple layers of NAT...in which case, the correct solution is to switch to a non-brain-damaged service ASAP. also, the problem with fetching a URL to find out your IP is that it only tells you the IP of the host that actually fetches it - which may be a proxy that strips Via headers.– casJul 20, 2009 at 9:51
If you facing a private ip of your isp and use some of firewall like cisco ASA, then you may setting up DNS Client and try to resolve fqdn myip.opendns.com quary in OpenDNS resolver to now that public ip you have from ISP.
SomeASA# show ip address
System IP Addresses:
Interface Name IP address Subnet mask Method
Vlan1 inside 10.10.10.1 255.255.255.248 CONFIG
Vlan2 outside 192.168.1.2 255.255.255.0 CONFIG
Current IP Addresses:
Interface Name IP address Subnet mask Method
Vlan1 inside 10.10.10.1 255.255.255.248 CONFIG
Vlan2 outside 192.168.1.2 255.255.255.0 CONFIG
SomeASA#
! - - Configure DNS client for OpenDNS resolver on ASA:
dns domain-lookup outside
dns server-group DefaultDNS
name-server 208.67.222.222
name-server 208.67.220.220
domain-name example.com
! - - and try to ping myip.opendns.com
SomeASA# ping myip.opendns.com
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
SomeASA#
! - - when DNS resolver return IP on fqdn myip.opendns.com request with IP what he that obtain from sources of ip address in request that arrives on resolver (in this example is resolver1.opendns.com [208.67.222.222] and resolver2.opendns.com [208.67.220.220])
SomeASA# show dns-hosts
Host Flags Age Type Address(es)
myip.opendns.com (temp, EX) 0 IP 1.1.1.1
SomeASA#
