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dockercontainersfirewalliptablesrules

Unable to append rules in iptable in docker

I am trying to add a rule which looks like:

Chain DOCKER (2 references)
target     prot opt source               destination
ACCEPT     tcp  --  anywhere             172.18.0.8           tcp dpt:21102

I am using the following command:

sudo iptables -A DOCKER -t tcp -s anywhere -d 172.18.0.8 --dport 21102 -j ACCEPT

However, I am getting the following error:

table 'tcp' does not exist
Perhaps iptables or your kernel needs to be upgraded.

Can someone please guide me where am I going wrong ?

Solution

  • -t : Specifies the packet matching table such as nat, filter, raw.etc

    -p : Sets the IP protocol for the rule, which can be either icmp, tcp, udp, or all.

    So the command should be:

    sudo iptables -A DOCKER -p tcp -s {source_ip} -d 172.18.0.8 --dport 21102 -j ACCEPT