The Nokia perimeter router must be configured to protect an enclave connected to an alternate gateway by using an inbound filter that only permits packets with destination addresses within the site's address space.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-283893 | NOKI-RT-000790 | SV-283893r1223374_rule | CCI-001414 | high |
| Description | ||||
| Enclaves with alternate gateway connections must take additional steps to ensure there is no compromise on the enclave network or NIPRNet. Without verifying the destination address of traffic coming from the site's alternate gateway, the perimeter router could be routing transit data from the internet into the NIPRNet. This could also make the perimeter router vulnerable to a denial-of-service attack and provide a back door into the NIPRNet. The DoW enclave must ensure the ingress filter applied to external interfaces on a perimeter router connecting to an approved gateway is secure through filters permitting packets with a destination address belonging to the DoW enclave's address block. | ||||
| STIG | Date | |||
| Nokia Service Router OS 25.x Router Security Technical Implementation Guide | 2026-06-15 | |||
Details
Check Text (C-283893r1223374_chk)
This requirement is not applicable for the DODIN Backbone.
Review the configuration of each router interface connecting to an alternate gateway.
Verify IPv4 and IPv6 filters are applied on the interface using the command below:
- show router interface "TO-PE2" detail | match "Ingress Filter"
Egress Filter : none Ingress Filter : 10
- show router interface "TO-PE2" detail | match "Ingr IPv6 Flt"
Egr IPv6 Flt : none Ingr IPv6 Flt : 80
If the ingress filter permits packets with addresses other than those specified, such as destination addresses of the site's NIPRNet address space or a destination address belonging to the address block assigned by the alternate gateway network service provider, this is a finding.
Fix Text (F-88363r1203927_fix)
This requirement is not applicable for the DODIN Backbone.
Configure the ingress filter of the perimeter router connected to an alternate gateway to only permit packets with destination addresses of the site's NIPRNet address space or a destination address belonging to the address block assigned by the alternate gateway network service provider.
Create an IPv4 filter using the example below:
- configure filter ip-filter 10
- config>filter>ip-filter# entry 10 create
- config>filter>ip-filter>entry$ match protocol "tcp"
- config>filter>ip-filter>entry>match$ exit
- config>filter>ip-filter>entry$ action forward
- config>filter>ip-filter>entry$ exit
- config>filter>ip-filter# entry 20 create
- config>filter>ip-filter>entry$ match protocol "icmp"
- config>filter>ip-filter>entry>match$ src-ip 10.12.1.16/32
- config>filter>ip-filter>entry>match$ dst-ip 10.12.2.17/32
- config>filter>ip-filter>entry>match$ icmp-type "echo-request"
- config>filter>ip-filter>entry>match$ exit
- config>filter>ip-filter>entry$ action forward
- config>filter>ip-filter>entry$ exit
- config>filter>ip-filter# entry 30 create
- config>filter>ip-filter>entry$ match protocol "icmp"
- config>filter>ip-filter>entry>match$ src-ip 10.12.1.16/32
- config>filter>ip-filter>entry>match$ dst-ip 10.12.2.17/32
- config>filter>ip-filter>entry>match$ icmp-type "echo-reply"
- config>filter>ip-filter>entry>match$ exit
- config>filter>ip-filter>entry$ action forward
- config>filter>ip-filter>entry$ exit
- config>filter>ip-filter# entry 40 create
- config>filter>ip-filter>entry$ match protocol "tcp"
- config>filter>ip-filter>entry>match$ dst-ip 10.12.2.17/32
- config>filter>ip-filter>entry>match$ dst-port 80 eq
- config>filter>ip-filter>entry>match$ exit
- config>filter>ip-filter>entry$ action forward
- config>filter>ip-filter>entry$ exit
- config>filter>ip-filter# entry 50 create
- config>filter>ip-filter>entry$ match dst-ip 10.12.2.17/32
- config>filter>ip-filter>entry>match# dst-port 80 eq
- config>filter>ip-filter>entry$ action forward
- config>filter>ip-filter>entry$ exit
- config>filter>ip-filter# entry 60 create
- config>filter>ip-filter>entry# match protocol 50
- config>filter>ip-filter>entry>match# exit
- config>filter>ip-filter>entry# action forward
- config>filter>ip-filter>entry# exit
- config>filter>ip-filter# entry 70 create
- config>filter>ip-filter>entry# match protocol 51
- config>filter>ip-filter>entry>match# exit
- config>filter>ip-filter>entry# action forward
- config>filter>ip-filter>entry# exit
- config>filter>ip-filter# default-action drop
- config>filter>ip-filter# exit all
Create an IPv6 filter using the example below:
- configure filter ipv6-filter 80 create
- config>filter>ipv6-filter# entry 10 create
- config>filter>ipv6-filter>entry# match next-header "tcp"
- config>filter>ipv6-filter>entry>match# tcp-established
- config>filter>ipv6-filter>entry>match# exit
- config>filter>ipv6-filter>entry# action forward
- config>filter>ipv6-filter>entry# exit
- config>filter>ipv6-filter# entry 20 create
- config>filter>ipv6-filter>entry# match next-header "ipv6-icmp"
- config>filter>ipv6-filter>entry>match# dst-ip 2001:acad:1234:50::2/128
- config>filter>ipv6-filter>entry>match# src-ip 2001:acad:1234:50::1/128 - config>filter>ipv6-filter>entry>match#icmp-type echo-request
- config>filter>ipv6-filter>entry>match# exit
- config>filter>ipv6-filter>entry# action forward
- config>filter>ipv6-filter>entry# exit
- config>filter>ipv6-filter# entry 30 create
- config>filter>ipv6-filter>entry# match next-header "ipv6-icmp"
- config>filter>ipv6-filter>entry>match# dst-ip 2001:acad:1234:50::2/128
- config>filter>ipv6-filter>entry>match# src-ip 2001:acad:1234:50::1/128 - config>filter>ipv6-filter>entry>match# icmp-type echo-reply
- config>filter>ipv6-filter>entry>match# exit
- config>filter>ipv6-filter>entry# action forward
- config>filter>ipv6-filter>entry# exit
- config>filter>ipv6-filter# entry 40 create
- config>filter>ipv6-filter>entry# match next-header "tcp"
- config>filter>ipv6-filter>entry>match# dst-ip 2001:acad:1234:50::2/128
- config>filter>ipv6-filter>entry>match# dst-port eq 80
- config>filter>ipv6-filter>entry>match# exit
- config>filter>ipv6-filter>entry# action forward
- config>filter>ipv6-filter>entry# exit
- config>filter>ipv6-filter# entry 50 create
- config>filter>ipv6-filter>entry# match next-header "tcp"
- config>filter>ipv6-filter>entry>match# dst-ip 2001:acad:1234:50::10/128
- config>filter>ipv6-filter>entry>match# dst-port eq 80
- config>filter>ipv6-filter>entry>match# exit
- config>filter>ipv6-filter>entry# action forward
- config>filter>ipv6-filter>entry# exit
- config>filter>ipv6-filter# entry 60 create
- config>filter>ipv6-filter>entry# match next-header 50
- config>filter>ipv6-filter>entry>match# exit
- config>filter>ipv6-filter>entry# action forward
- config>filter>ipv6-filter>entry# exit
- config>filter>ipv6-filter# entry 70 create
- config>filter>ipv6-filter>entry# match next-header 51
- config>filter>ipv6-filter>entry>match# exit
- config>filter>ipv6-filter>entry# action forward
- config>filter>ipv6-filter>entry# exit
- config>filter>ipv6-filter# default-action drop
- config>filter>ipv6-filter#
Apply IPv4 and IPv6 filters on the interface using the example below:
- configure router interface "TO-PE2" ingress filter ip 10
- configure router interface "TO-PE2" ingress filter ipv6 80