Accessing FTP server tests via a router static pat

1. Test topology:

R2 (FTP Client 202.100.1.2/24)-------------------(202.100.1.2/24) R1 (10.1.1.1/24)---------------------(10.1.1.18/ ) FTP Server

Reference links: Processing of FTP in Http://www.zhangdaqian.net/blog/atpat, and the non-standard 21-FTP port settings after Pat. htm

2. Test objectives:

Through testing, understand the two modes of ftp: Passive mode, active mode

A. Passive mode:

Command:client (source port >tcp 1024)------>ftp Server (Destination port TCP 21)

Data:client (Destination port >tcp 1024)------> FTP Server (Source port >tcp 1024)

B. Active mode:

Command:client (source port >tcp 1024)------>ftp Server (Destination port TCP 21)

Data:client (Destination port >tcp 1024) <------FTP Server (source port TCP 20)

3. Basic configuration:

A.R1:

Config T

Interface ethernet0/0

IP address 202.100.1.1 255.255.255.0

No shutdown

Interface ETHERNET0/1

IP address 10.1.1.1 255.255.255.0

No shutdown

B.R2:

Config T

Interface ethernet0/0

IP address 202.100.1.2 255.255.255.0

No shutdown

C.ftp Server:

Ip:10.1.1.18/25

gw:10.1.1.1

4.R1 Router Pat configuration:

A. Only static PAT is configured first

Config T

Interface ethernet0/0

IP Nat Outside

Interface ETHERNET0/1

IP nat Inside

IP nat inside source static TCP 10.1.1.18 interface e0/0 21