DROP or REJECT packets from PREROUTING NAT table in iptables
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Goal is to allow only specific networks to access docker container services/ports running on my server.
Tried adding ACCEPT rules in to INPUT filter chain. That did not help, networks even without ACCEPT rule were still able to access docker service/port.
Tried adding ACCEPT and DROP rules in FORWARD chain, this works. But this has many disadvantages like: a. Rules getting deleted or re-positioned on docker restart b. Rules can become invalid, if docker containers are re-deployed and get different IPs at runtime
Plan is to BLOCK them before even reaching FORWARD chain.
So, added a new chain in NAT table, which redirects to DOCKER chain if traffic is from allowed network, if it is from other networks, added DNAT to a BLOCKHOLE IP. In PREROUTING, first rule is to jump to this chain.This seems to be working.
DNAT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:1234 to:0.0.0.1
But, instead of redirecting it to a BLOCKHOLE, can we somehow REJECT this traffic so that the client knows it is not allowed and hence refused.
iptables nat
asked Aug 31 at 9:36
Ram
126113
add a comment |Â
up vote
1
down vote
favorite
Goal is to allow only specific networks to access docker container services/ports running on my server.
Tried adding ACCEPT rules in to INPUT filter chain. That did not help, networks even without ACCEPT rule were still able to access docker service/port.
Tried adding ACCEPT and DROP rules in FORWARD chain, this works. But this has many disadvantages like: a. Rules getting deleted or re-positioned on docker restart b. Rules can become invalid, if docker containers are re-deployed and get different IPs at runtime
Plan is to BLOCK them before even reaching FORWARD chain.
So, added a new chain in NAT table, which redirects to DOCKER chain if traffic is from allowed network, if it is from other networks, added DNAT to a BLOCKHOLE IP. In PREROUTING, first rule is to jump to this chain.This seems to be working.
DNAT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:1234 to:0.0.0.1
But, instead of redirecting it to a BLOCKHOLE, can we somehow REJECT this traffic so that the client knows it is not allowed and hence refused.
iptables nat
asked Aug 31 at 9:36
Ram
126113
Tried: DNAT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:1234 to:<Server-IP> And catch the same port traffic in INPUT filter and DROP/REJECT. Even then the client gets 'Connection Timedout'. So its same behavior even if we direct the traffic to a BLOCKHOLE.
– Ram
Aug 31 at 10:10
add a comment |Â
up vote
1
down vote
favorite
up vote
1
down vote
favorite
Goal is to allow only specific networks to access docker container services/ports running on my server.
Tried adding ACCEPT rules in to INPUT filter chain. That did not help, networks even without ACCEPT rule were still able to access docker service/port.
Tried adding ACCEPT and DROP rules in FORWARD chain, this works. But this has many disadvantages like: a. Rules getting deleted or re-positioned on docker restart b. Rules can become invalid, if docker containers are re-deployed and get different IPs at runtime
Plan is to BLOCK them before even reaching FORWARD chain.
So, added a new chain in NAT table, which redirects to DOCKER chain if traffic is from allowed network, if it is from other networks, added DNAT to a BLOCKHOLE IP. In PREROUTING, first rule is to jump to this chain.This seems to be working.
DNAT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:1234 to:0.0.0.1
But, instead of redirecting it to a BLOCKHOLE, can we somehow REJECT this traffic so that the client knows it is not allowed and hence refused.
iptables nat
asked Aug 31 at 9:36
Ram
126113
Goal is to allow only specific networks to access docker container services/ports running on my server.
Tried adding ACCEPT rules in to INPUT filter chain. That did not help, networks even without ACCEPT rule were still able to access docker service/port.
Tried adding ACCEPT and DROP rules in FORWARD chain, this works. But this has many disadvantages like: a. Rules getting deleted or re-positioned on docker restart b. Rules can become invalid, if docker containers are re-deployed and get different IPs at runtime
Plan is to BLOCK them before even reaching FORWARD chain.
So, added a new chain in NAT table, which redirects to DOCKER chain if traffic is from allowed network, if it is from other networks, added DNAT to a BLOCKHOLE IP. In PREROUTING, first rule is to jump to this chain.This seems to be working.
DNAT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:1234 to:0.0.0.1
But, instead of redirecting it to a BLOCKHOLE, can we somehow REJECT this traffic so that the client knows it is not allowed and hence refused.
iptables nat
iptables nat
asked Aug 31 at 9:36
Ram
126113
asked Aug 31 at 9:36
Ram
126113
asked Aug 31 at 9:36
Ram
126113
asked Aug 31 at 9:36
Ram
126113
asked Aug 31 at 9:36
Ram
126113
126113
Tried: DNAT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:1234 to:<Server-IP> And catch the same port traffic in INPUT filter and DROP/REJECT. Even then the client gets 'Connection Timedout'. So its same behavior even if we direct the traffic to a BLOCKHOLE.
– Ram
Aug 31 at 10:10
add a comment |Â
Tried: DNAT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:1234 to:<Server-IP> And catch the same port traffic in INPUT filter and DROP/REJECT. Even then the client gets 'Connection Timedout'. So its same behavior even if we direct the traffic to a BLOCKHOLE.
– Ram
Aug 31 at 10:10
Tried: DNAT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:1234 to:<Server-IP> And catch the same port traffic in INPUT filter and DROP/REJECT. Even then the client gets 'Connection Timedout'. So its same behavior even if we direct the traffic to a BLOCKHOLE.
– Ram
Aug 31 at 10:10
Tried: DNAT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:1234 to:<Server-IP> And catch the same port traffic in INPUT filter and DROP/REJECT. Even then the client gets 'Connection Timedout'. So its same behavior even if we direct the traffic to a BLOCKHOLE.
– Ram
Aug 31 at 10:10
add a comment |Â
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Tried: DNAT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:1234 to:<Server-IP> And catch the same port traffic in INPUT filter and DROP/REJECT. Even then the client gets 'Connection Timedout'. So its same behavior even if we direct the traffic to a BLOCKHOLE.
– Ram
Aug 31 at 10:10