$ telnet 192.168.1.1 21
Trying 192.168.1.1...
Connected to 192.168.1.1.
Escape character is '^]'.
220 ADAM2 FTP Server ready.
USER adam2
331 Password required for adam2.
PASS adam2
230 User adam2 successfully logged in.
GETENV mtd0
mtd0                  0x900a1000,0x903f0000
200 GETENV command successful
GETENV mtd1
mtd1                  0x90010090,0x900a1000
200 GETENV command successful
GETENV mtd2
mtd2                  0x90000000,0x90010000
200 GETENV command successful
GETENV mtd3
mtd3                  0x903f0000,0x90400000
200 GETENV command successful
GETENV mtd4
mtd4                  0x90010000,0x903f0000
200 GETENV command successful
GETENV mtd5
501 mtd5 environment variable not set.