113.x.x.x是A类IP地址，占全球IP地址的250分之一，遍布全中国都有这样的IP。
介绍一下IP地址的分配：
所有的IP地址都由国际组织NIC（Network Information
Center）负责统一分配，目前全世界共有三个这样的网络信息中心。
InterNIC：负责美国及其他地区；
ENIC：负责欧洲地区；
APNIC：负责亚太地区。
我国申请IP地址要通过APNIC，APNIC的总部设在日本东京大学。
113开头的地址分配到了很多国家，不止中国一个：
apnic|CN|ipv4|113.0.0.0|524288|20080916|allocated
apnic|CN|ipv4|113.8.0.0|131072|20080916|allocated
apnic|KR|ipv4|113.10.0.0|16384|20080917|allocated
apnic|SG|ipv4|113.10.64.0|16384|20080922|allocated
apnic|HK|ipv4|113.10.128.0|32768|20080923|allocated
apnic|BD|ipv4|113.11.0.0|32768|20080923|allocated
apnic|ID|ipv4|113.11.128.0|8192|20080924|allocated
apnic|SG|ipv4|113.11.160.0|4096|20080926|allocated
apnic|ID|ipv4|113.11.176.0|2048|20080926|assigned
apnic|AU|ipv4|113.11.184.0|1024|20080929|allocated
apnic|MY|ipv4|113.11.188.0|1024|20101223|allocated
apnic|CN|ipv4|113.11.192.0|8192|20080929|allocated
apnic|IN|ipv4|113.11.224.0|2048|20080930|allocated
apnic|AU|ipv4|113.11.232.0|1024|20081001|allocated
apnic|MY|ipv4|113.11.236.0|1024|20101223|assigned
apnic|VU|ipv4|113.11.240.0|2048|20081002|allocated
apnic|SG|ipv4|113.11.248.0|2048|20110311|allocated
apnic|CN|ipv4|113.12.0.0|262144|20080918|allocated
apnic|CN|ipv4|113.16.0.0|131072|20080918|allocated
apnic|CN|ipv4|113.18.0.0|65536|20080929|allocated
apnic|IN|ipv4|113.19.0.0|65536|20080930|allocated
apnic|AU|ipv4|113.20.0.0|4096|20081002|allocated
apnic|IN|ipv4|113.20.16.0|1024|20100111|allocated
apnic|HK|ipv4|113.20.20.0|1024|20100112|allocated
apnic|AU|ipv4|113.20.24.0|1024|20100112|allocated
apnic|ID|ipv4|113.20.28.0|1024|20110110|allocated
apnic|NC|ipv4|113.20.32.0|4096|20081002|allocated
apnic|NC|ipv4|113.20.48.0|4096|20100209|allocated
apnic|FJ|ipv4|113.20.64.0|8192|20081002|allocated
apnic|VN|ipv4|113.20.96.0|8192|20110211|allocated
apnic|AU|ipv4|113.20.128.0|1024|20081006|allocated
apnic|HK|ipv4|113.20.132.0|1024|20101223|allocated
apnic|ID|ipv4|113.20.136.0|2048|20081010|allocated
apnic|PH|ipv4|113.20.144.0|2048|20081010|allocated
apnic|JP|ipv4|113.20.152.0|1024|20081013|allocated
apnic|PH|ipv4|113.20.160.0|8192|20081008|allocated
apnic|JP|ipv4|113.20.192.0|16384|20081006|allocated
apnic|KR|ipv4|113.21.0.0|8192|20081009|allocated
apnic|AU|ipv4|113.21.32.0|4096|20081106|allocated
apnic|JP|ipv4|113.21.48.0|4096|20081013|allocated
apnic|IN|ipv4|113.21.64.0|4096|20090814|allocated
apnic|TW|ipv4|113.21.80.0|4096|20081014|allocated
apnic|NC|ipv4|113.21.96.0|4096|20081009|allocated
apnic|NC|ipv4|113.21.112.0|4096|20091028|allocated
apnic|MY|ipv4|113.21.128.0|8192|20081009|allocated
apnic|TW|ipv4|113.21.160.0|8192|20081010|allocated
apnic|HK|ipv4|113.21.192.0|8192|20081015|allocated
apnic|NZ|ipv4|113.21.224.0|1024|20081015|allocated
apnic|BD|ipv4|113.21.228.0|1024|20090422|allocated
apnic|TH|ipv4|113.21.240.0|2048|20081016|allocated
apnic|JP|ipv4|113.21.248.0|2048|20081017|allocated
apnic|VN|ipv4|113.22.0.0|65536|20081010|allocated
apnic|VN|ipv4|113.23.0.0|32768|20081010|allocated
apnic|MY|ipv4|113.23.128.0|32768|20081014|allocated
apnic|CN|ipv4|113.24.0.0|262144|20081013|allocated
apnic|HK|ipv4|113.28.0.0|65536|20081013|allocated
apnic|US|ipv4|113.29.0.0|32768|20081016|allocated
apnic|KR|ipv4|113.29.128.0|16384|20081017|allocated
apnic|KR|ipv4|113.29.192.0|4096|20081017|allocated
apnic|AU|ipv4|113.29.208.0|2048|20081017|allocated
apnic|JP|ipv4|113.29.216.0|2048|20081020|allocated
apnic|SG|ipv4|113.29.224.0|4096|20081017|allocated
apnic|AU|ipv4|113.29.240.0|1024|20081021|allocated
apnic|AU|ipv4|113.29.244.0|1024|20101223|allocated
apnic|KH|ipv4|113.29.248.0|1024|20081021|allocated
apnic|HK|ipv4|113.29.252.0|1024|20081027|allocated
apnic|KR|ipv4|113.30.0.0|16384|20081017|allocated
apnic|KR|ipv4|113.30.64.0|16384|20081017|allocated
apnic|IN|ipv4|113.30.128.0|32768|20081017|allocated
apnic|CN|ipv4|113.31.0.0|65536|20081017|allocated
apnic|JP|ipv4|113.32.0.0|524288|20081015|allocated
apnic|JP|ipv4|113.40.0.0|262144|20081015|allocated
apnic|CN|ipv4|113.44.0.0|262144|20081015|allocated
apnic|CN|ipv4|113.48.0.0|262144|20081016|allocated
apnic|AU|ipv4|113.52.0.0|4096|20081020|allocated
apnic|JP|ipv4|113.52.16.0|4096|20110310|allocated
apnic|VN|ipv4|113.52.32.0|8192|20081021|allocated
apnic|MO|ipv4|113.52.64.0|16384|20081022|allocated
apnic|AU|ipv4|113.52.128.0|1024|20081022|allocated
apnic|HK|ipv4|113.52.132.0|1024|20101223|allocated
apnic|KR|ipv4|113.52.136.0|2048|20081027|allocated
apnic|AU|ipv4|113.52.144.0|1024|20081028|allocated
apnic|ID|ipv4|113.52.148.0|1024|20101224|assigned
apnic|SG|ipv4|113.52.152.0|1024|20081030|allocated
apnic|JP|ipv4|113.52.156.0|1024|20081110|allocated
apnic|CN|ipv4|113.52.160.0|8192|20081023|allocated
apnic|KR|ipv4|113.52.192.0|8192|20081027|allocated
apnic|AU|ipv4|113.52.232.0|2048|20081027|allocated
apnic|JP|ipv4|113.52.240.0|4096|20110310|allocated
apnic|TH|ipv4|113.53.0.0|65536|20081022|allocated
apnic|CN|ipv4|113.54.0.0|131072|20081022|allocated
apnic|CN|ipv4|113.56.0.0|131072|20081024|allocated
apnic|CN|ipv4|113.58.0.0|65536|20081027|allocated
apnic|CN|ipv4|113.59.0.0|32768|20081027|allocated
apnic|KR|ipv4|113.59.128.0|16384|20081028|allocated
apnic|LK|ipv4|113.59.192.0|8192|20081028|allocated
apnic|CN|ipv4|113.59.224.0|1024|20110414|allocated
apnic|JP|ipv4|113.59.228.0|1024|20091028|allocated
apnic|ID|ipv4|113.59.232.0|2048|20081105|allocated
apnic|HK|ipv4|113.59.240.0|4096|20081031|allocated
apnic|KR|ipv4|113.60.0.0|65536|20081027|allocated
apnic|KR|ipv4|113.61.0.0|8192|20081103|allocated
apnic|PH|ipv4|113.61.32.0|8192|20081103|allocated
apnic|AU|ipv4|113.61.64.0|8192|20081104|allocated
apnic|AU|ipv4|113.61.96.0|2048|20081106|allocated
apnic|KR|ipv4|113.61.104.0|1024|20081113|assigned
apnic|VN|ipv4|113.61.108.0|1024|20081113|assigned
apnic|JP|ipv4|113.61.112.0|4096|20081110|allocated
apnic|TW|ipv4|113.61.128.0|32768|20081106|allocated
apnic|CN|ipv4|113.62.0.0|131072|20081031|allocated
apnic|CN|ipv4|113.64.0.0|2097152|20081103|allocated
apnic|CN|ipv4|113.96.0.0|1048576|20081103|allocated
apnic|CN|ipv4|113.112.0.0|524288|20081103|allocated
apnic|CN|ipv4|113.120.0.0|524288|20081103|allocated
apnic|CN|ipv4|113.128.0.0|131072|20081103|allocated
apnic|JP|ipv4|113.130.0.0|16384|20081107|allocated
apnic|KR|ipv4|113.130.64.0|8192|20081114|allocated
apnic|CN|ipv4|113.130.96.0|4096|20081114|allocated
apnic|CN|ipv4|113.130.112.0|2048|20081114|allocated
apnic|NZ|ipv4|113.130.120.0|1024|20081114|allocated
apnic|KH|ipv4|113.130.124.0|1024|20101224|allocated
apnic|KR|ipv4|113.130.128.0|32768|20081110|allocated
apnic|KR|ipv4|113.131.0.0|65536|20081110|allocated
apnic|CN|ipv4|113.132.0.0|262144|20081106|allocated
apnic|CN|ipv4|113.136.0.0|524288|20081106|allocated
apnic|JP|ipv4|113.144.0.0|1048576|20081110|allocated
apnic|VN|ipv4|113.160.0.0|2097152|20081104|allocated
apnic|AU|ipv4|113.192.0.0|16384|20081113|allocated
apnic|KR|ipv4|113.192.64.0|16384|20110202|allocated
apnic|JP|ipv4|113.192.128.0|32768|20081118|allocated
apnic|IN|ipv4|113.193.0.0|65536|20081119|allocated
apnic|CN|ipv4|113.194.0.0|131072|20081119|allocated
apnic|TW|ipv4|113.196.0.0|65536|20081120|allocated
apnic|AU|ipv4|113.197.0.0|4096|20081121|allocated
apnic|JP|ipv4|113.197.16.0|4096|20110310|allocated
apnic|SG|ipv4|113.197.32.0|2048|20081126|allocated
apnic|JP|ipv4|113.197.40.0|2048|20081202|allocated
apnic|PK|ipv4|113.197.48.0|2048|20081201|allocated
apnic|JP|ipv4|113.197.56.0|2048|20110315|allocated
apnic|NZ|ipv4|113.197.64.0|1024|20081202|allocated
apnic|PF|ipv4|113.197.68.0|1024|20101224|allocated
apnic|PH|ipv4|113.197.72.0|2048|20081202|allocated
apnic|KR|ipv4|113.197.80.0|4096|20081203|allocated
apnic|NZ|ipv4|113.197.96.0|1024|20081204|allocated
apnic|CN|ipv4|113.197.100.0|1024|20101229|allocated
apnic|IN|ipv4|113.197.104.0|1024|20081205|allocated
apnic|ID|ipv4|113.197.108.0|1024|20110110|allocated
apnic|AU|ipv4|113.197.112.0|4096|20081205|allocated
apnic|JP|ipv4|113.197.128.0|32768|20081126|allocated
apnic|KR|ipv4|113.198.0.0|65536|20081126|allocated
apnic|KR|ipv4|113.199.0.0|32768|20081126|allocated
apnic|NP|ipv4|113.199.128.0|32768|20081202|allocated
apnic|CN|ipv4|113.200.0.0|131072|20081126|allocated
apnic|CN|ipv4|113.202.0.0|65536|20081128|allocated
apnic|AU|ipv4|113.203.0.0|32768|20081128|allocated
apnic|PK|ipv4|113.203.128.0|32768|20101224|allocated
apnic|CN|ipv4|113.204.0.0|262144|20081126|allocated
apnic|JP|ipv4|113.208.0.0|16384|20081203|allocated
apnic|HK|ipv4|113.208.64.0|8192|20081205|allocated
apnic|CN|ipv4|113.208.96.0|8192|20081205|allocated
apnic|CN|ipv4|113.208.128.0|32768|20081205|allocated
apnic|CN|ipv4|113.209.0.0|65536|20081204|allocated
apnic|MY|ipv4|113.210.0.0|131072|20081203|allocated
apnic|CN|ipv4|113.212.0.0|16384|20081205|allocated
apnic|IN|ipv4|113.212.64.0|8192|20081208|allocated
apnic|AU|ipv4|113.212.96.0|1024|20081209|allocated
apnic|CN|ipv4|113.212.100.0|1024|20101229|allocated
apnic|JP|ipv4|113.212.104.0|1024|20081210|allocated
apnic|MY|ipv4|113.212.108.0|1024|20081217|allocated
apnic|ID|ipv4|113.212.112.0|4096|20081210|allocated
apnic|JP|ipv4|113.212.128.0|8192|20081209|allocated
apnic|ID|ipv4|113.212.160.0|2048|20081210|allocated
apnic|AU|ipv4|113.212.168.0|1024|20081215|allocated
apnic|AU|ipv4|113.212.172.0|1024|20100504|allocated
apnic|PH|ipv4|113.212.176.0|2048|20081215|allocated
apnic|CN|ipv4|113.212.184.0|2048|20110412|allocated
apnic|HK|ipv4|113.212.192.0|16384|20081216|allocated
apnic|CN|ipv4|113.213.0.0|32768|20081217|allocated
apnic|JP|ipv4|113.213.128.0|16384|20081219|allocated
apnic|JP|ipv4|113.213.192.0|8192|20081222|allocated
apnic|JP|ipv4|113.213.224.0|4096|20081222|allocated
apnic|JP|ipv4|113.213.240.0|4096|20081223|allocated
apnic|CN|ipv4|113.214.0.0|131072|20081208|allocated
apnic|KR|ipv4|113.216.0.0|131072|20081215|allocated
apnic|CN|ipv4|113.218.0.0|131072|20081216|allocated
apnic|CN|ipv4|113.220.0.0|262144|20081216|allocated
apnic|CN|ipv4|113.224.0.0|1048576|20081208|allocated
apnic|CN|ipv4|113.240.0.0|524288|20081216|allocated
apnic|CN|ipv4|113.248.0.0|262144|20081216|allocated
apnic|HK|ipv4|113.252.0.0|262144|20081218|allocated
