diff options
| author | Kevin Wallace <kevin@pentabarf.net> | 2017-05-24 23:07:01 -0700 |
|---|---|---|
| committer | Kevin Wallace <kevin@pentabarf.net> | 2017-05-24 23:10:33 -0700 |
| commit | e1581a5fbdf40ba9132da3558a03e685a449b08f (patch) | |
| tree | 4cc9ee18709997457132014d559aadfa18301b6d | |
| parent | use stderr responsibly (diff) | |
readme
| -rw-r--r-- | README.md | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/README.md b/README.md new file mode 100644 index 0000000..cb12050 --- /dev/null +++ b/README.md @@ -0,0 +1,78 @@ +# rdns +Quickly look up reverse DNS names. One of them or lots of them. + +Look them up by IPv4 address: +```sh +$ rdns 192.0.43.7 +# 192.0.43.7 +192.0.43.7 icann.org. +``` +Look them up by IPv6 address: +```sh +$ rdns 2001:500:88:200::8 +# 2001:500:88:200::8 +2001:500:88:200::8 iana.org. +``` +Look up ranges of them: +```sh +$ rdns 192.0.43.7/29 +# 192.0.43.7/29 +192.0.43.0 # error: lookup 192.0.43.0: nodename nor servname provided, or not known +192.0.43.1 43-1.any.icann.org. +192.0.43.2 43-2.any.icann.org. +192.0.43.3 43-3.any.icann.org. +192.0.43.4 43-4.any.icann.org. +192.0.43.5 43-5.any.icann.org. +192.0.43.6 43-6.any.icann.org. +192.0.43.7 icann.org. +``` +Look them up by forward name: +```sh +$ rdns arin.net +# arin.net +2001:500:4:c000::43 www.arin.net. +2001:500:4:c000::44 www.arin.net. +199.43.0.43 www.arin.net. +199.43.0.44 www.arin.net. +``` +Look them up by all of the above at once: +```sh +$ rdns 192.0.43.7 2001:500:88:200::8 192.0.43.7/29 arin.net +# 192.0.43.7 +192.0.43.7 icann.org. +# 2001:500:88:200::8 +2001:500:88:200::8 iana.org. +# 192.0.43.7/29 +192.0.43.0 # error: lookup 192.0.43.0: nodename nor servname provided, or not known +192.0.43.1 43-1.any.icann.org. +192.0.43.2 43-2.any.icann.org. +192.0.43.3 43-3.any.icann.org. +192.0.43.4 43-4.any.icann.org. +192.0.43.5 43-5.any.icann.org. +192.0.43.6 43-6.any.icann.org. +192.0.43.7 icann.org. +# arin.net +2001:500:4:c000::43 www.arin.net. +2001:500:4:c000::44 www.arin.net. +199.43.0.43 www.arin.net. +199.43.0.44 www.arin.net. +``` +Errors go to stderr so they're easy to filter out if you're scanning a sparse net and don't care about failures: +```sh +$ rdns 4.2.2.0/27 2>/dev/null +# 4.2.2.0/27 +4.2.2.1 a.resolvers.level3.net. +4.2.2.2 b.resolvers.level3.net. +4.2.2.3 c.resolvers.level3.net. +4.2.2.4 d.resolvers.level3.net. +4.2.2.5 e.resolvers.level3.net. +4.2.2.6 f.resolvers.level3.net. +4.2.2.12 test-record.level3.net. +``` + +## Installation +```sh +$ go install github.com/kevinwallace/rdns +``` + +Happy resolving. |