UDP ports blocked... Or are they?
Wed, 4 Jul 2001 03:42:14 +1000
When doing some scans of my firewall with nmap using this command: nmap -sU -p
1-100 -O xxx.xxx.xxx.xxx So basically just a udp scan.
I see a heap of logs similar to the following in my logs.
July kernel: IPT IN_DROP: IN=eth0 LEN=328 TOS=0x00 PREC=0x00 TTL=50 ID=56753
PROTO=UDP SPT=42328 DPT=51 LEN=308
but nmap reports:
Port State Service
1/udp open tcpmux
2/udp open compressnet
3/udp open compressnet
4/udp open unknown
5/udp open rje
6/udp open unknown
7/udp open echo
Can someone explain what is going on. Iptables tells me it's dropping the
packets but nmap says that those ports are open not filtered?