CNFs NAT46

Overview

Cloud-Native Network Functions (CNFs) NAT46 provides the ability to process IPv4 to IPv6 application traffic, specifically between IPv4 only clients and IPv6 only servers. To provide NAT46, the Service Proxy Traffic Management Microkernel (TMM) Proxy Pod uses an IPv4 virtual server to receive connections, and load balancing connections to IPv6 pool members as the packet destinations. The Service Proxy TMM Pod translate the source IP address of egress network packets to IPv6 using source network address translation (SNAT).

Connection example

When the IPv4 client requires a connection to IPv6 server www.46test.com, the TMM Proxy Pod’s virtual server receives the connection for 10.30.2.1, and load balances the connection to one of the pool members using the pool member’s IP address 2002::10:30:2:220 as the destination. When the IPv4 client connects to 10.30.2.1 through the TMM Proxy Pod, the network packet is sent to destination address 2002::10:30:2:220, using the source IP address 2002::10:30:2:111 selected from the configured SNAT pool. Connections between the endpoints continue to flow through the TMM Proxy Pod for the life of the connection.

Required CNFs CRs

NAT46 requires CNFs Custom Resources (CRs) installed in this order:

  • The F5BigNetVlan specifies clientside IPv4 and serverside IPv6 addresses.
  • The F5BigCneSnatpool specifies IPv6 addresses used to translate subscriber connections.
  • The optional F5BigFwPolicy filters application connections by IP address.
  • The optional F5BigLogProfile sends connection events to remote logging servers.
  • The F5BigContextSecure processes and load balances subscriber connections.

This document describes, and guides you through the DNS46 implementation.

Requirements

Ensure you have:

Installation

Use this installation procedure to configure NAT46.

_images/spk_info.png Tip: Open a second shell to view the CNFs Event Logs while installing.

  1. The example F5BigNetVlan CR configures IPv4 addresses on the clientside, and IPv6 addresses on the serverside for up to 2 TMM Proxy Pods. Copy and paste the example CR into a YAML file:

    Note: You can configure both IPv4 and IPv6 addresses on each VLAN.

    apiVersion: "k8s.f5net.com/v1"
    kind: F5BigNetVlan
    metadata:
      name: "subscriber-vlan"
      namespace: "cnf-gateway"
    spec:
      name: clientside
      interfaces:
        - "1.1"
      selfip_v4s:
        - 10.10.10.100
        - 10.10.10.101
      prefixlen_v4: 24
      cmp_hash: DST_ADDR
    ---
    apiVersion: "k8s.f5net.com/v1"
    kind: F5BigNetVlan
    metadata:
      name: "application-vlan"
      namespace: "cnf-gateway"
    spec:
      name: serverside
      interfaces:
        - "1.2"
      selfip_v6s:
        - 2002::192:168:10:100
        - 2002::192:168:10:101
      prefixlen_v6: 116
      mtu: 9000
      cmp_hash: SRC_ADDR
    
  2. Install the F5BigNetVlan CR:

    In this example, the BIG-IP Controller logs indicate the F5BigNetVlan CRs were added/updated:

    I0613 12:00:00:12345    1 event.go:282] Event(v1.ObjectReference{Kind:"F5Vlan", 
    F5Vlan cnf-gateway/subscriber-vlan was added/updated
    
    I0613 12:00:00:12345    1 event.go:282] Event(v1.ObjectReference{Kind:"F5Vlan", 
    F5Vlan cnf-gateway/application-vlan was added/updated
    
  3. The example F5BigCneSnatpool CR configures up to 2 TMM Pods with 4 IPv6 address to translate egress connections. Copy and paste the example CR into a YAML file:

    Note: The F5BigCneSnatpool CR will be referenced by the F5BigContextSecure CR.

    apiVersion: "k8s.f5net.com/v1"
    kind: F5BigCneSnatpool
    metadata:
      name: "46-snatpool"
      namespace: "cnf-gateway"
    spec:
      name: "46_snatpool"
      addressList:
        - - 2002::10:30:2:111
          - 2002::10:30:2:112
          - 2002::10:30:2:113
          - 2002::10:30:2:114
        - - 2002::10:30:2:115
          - 2002::10:30:2:116
          - 2002::10:30:2:117
          - 2002::10:30:2:118
    
  4. Install the F5BigCneSnatpool CR:

    oc apply -f f5-cnf-snatpool.yaml
    

    In this example, the BIG-IP Controller logs indicate the F5BigCneSnatpool CR was added/updated:

    I0202 12:00:00:12350    1 event.go:282] Event(v1.ObjectReference{Kind:"F5Snatpool", 
    F5Snatpool cnf-gateway/46_snatpool was added/updated
    
  5. Optional: The example F5BigLogHslpub CR specifies a remote server with IP/port [2002::10:30:2:220]:514, and the udp protocol. Copy and paste the example into a YAML file:

    Note: The F5BigLogHslpub CR will be referenced by the F5BigLogProfile.

    apiVersion: k8s.f5net.com/v1
    kind: F5BigLogHslpub
    metadata:
      name: "cnf-hsl-pub"
      namespace: "cnf-gateway"
    spec:
      pool:
      - name: "hsl-pool"
        endpoint:
        - "[2002::10:30:2:220]:514"
      syslog:
      - name: "cnf-syslog"
        format: "rfc5424"
        protocol: "udp"
        pool: "hsl-pool"
    
  6. Install the F5BigLogHslpub CR:

    oc apply -f cnf-hsl-cr.yaml
    

    In this example, the BIG-IP Controller logs indicate the F5BigLogHslpub CR was added/updated:

    I0202 12:00:00.12347   1 event.go:282 Event(v1.ObjectReference{Kind:"F5Hslpub",
    F5Hslpub cnf-gateway/cnf-hsl-pub was added/updated
    
  7. Optional: The example F5BigLogProfile CR captures firewall events such as packet match and drop. Copy and paste the CR nto a YAML file:

    Note: The F5BigLogProfile CR will be referenced by the F5BigContextSecure CR.

    apiVersion: "k8s.f5net.com/v1"
    kind: F5BigLogProfile
    metadata:
      name: "cnf-log-profile"
      namespace: "cnf-gateway"
    spec:
      name: "cnf-logs"
      firewall:
        enabled: true
        network:
          publisher: "cnf-hsl-pub"
          events:
            aclMatchAccept: true
            aclMatchDrop: true
            tcpEvents: true
            translationFields: true
    
  8. Install the F5BigLogProfile CR:

    oc apply -f cnf-log-cr.yaml
    

    In this example, the BIG-IP Controller logs indicate the F5BigLogProfile CR was added/updated:

    I0202 12:00:00.12348   1 event.go:282 Event(v1.ObjectReference{Kind:"F5LogProfile",
    LogProfile cnf-gateway/log_profile1 was added/updated
    
  9. Optional: The example F5BigFwPolicy CR allows connectivity only from the IPv4 prefix 10.20.2.0/24. Copy and paste the CR into a YAML file:

    Note: The F5BigFwPolicy CR will be referenced by the F5BigContextSecure CR.

    apiVersion: "k8s.f5net.com/v1"
    kind: F5BigFwPolicy
    metadata:
      name: "cnf-fw-46"
      namespace: "cnf-gateway"
    spec:
      rule:
       - name: allow-10-20
         action: "accept"
         logging: true
         ipProtocol: any
         source:
           addresses:
             - "10.20.2.0/24"
       - name: drop-all
         action: "drop"
         logging: true
         ipProtocol: any
         source:
           addresses:
             - "0.0.0.0/0"
    
  10. Install the F5BigFwPolicy CR:

    oc apply -f cnf-fw-cr.yaml
    

    In this example, the BIG-IP Controller logs indicate the F5BigFwPolicy CR was added/updated:

    I0202 12:00:00.12346   1 event.go:282 Event(v1.ObjectReference{Kind:"F5FirewallPolicy", 
    FirewallPolicy cnf-gateway/cnf-fw-46 was added/updated
    
  11. The F5BigContextSecure CR accepts packets on the subscriber-vlan interface destined to the 10.30.2.0/24 IPv4 prefix, and load balances the packets to the 2002::10:30:2:220 and 2002::10:30:2:221 destination IP addresses. A translated client source IPv6 address will be selected from the installed F5BigCneSnatpool. Copy and paste the CR into a YAML file:

    apiVersion: k8s.f5net.com/v1
    kind: F5BigContextSecure
    metadata:
      name: "cnf-46-context"
      namespace: "cnf-gateway"
    spec:
       destinationAddress: "10.30.2.0/24"
       destinationPort: 0
       ipProtocol: "any"
       profile: "fastL4"
       firewallEnforcedPolicy: "cnf-fw-46"
       logProfile: "cnf-log-profile"
       vlans:
          vlanList: 
            - "subscriber-vlan"
       snat: 
         type: "snat"
         pool: "46_snatpool"
       pool:
         members:
           - address: "2002::10:30:2:220"
           - address: "2002::10:30:2:221"
    
  12. Install the F5BigContextSecure CR:

    oc apply -f f5-cnf-46-context.yaml
    

    In this example, the BIG-IP Controller logs indicate the F5BigContextSecure CR was added/updated:

    I0202 12:00:00:12350    1 event.go:282] Event(v1.ObjectReference{Kind:"F5SecureContext", 
    F5SecureContext cnf-gateway/cnf-46-context was added/updated
    
  13. Continue to the Traffic statistics section.

Traffic statistics

If you have installed the TMM Debug container, use the following steps to gather traffic processing statistics for the F5BigNatPolicy, F5BigFwPolicy and F5BigContextSecure CRs.

  1. Log in to the TMM debug Pod:

    In this example, the TMM debug container is in the cnf-gateway namespace:

    oc exec -it deploy/f5-tmm -c debug -n cnf-gateway -- bash
    
  2. Verify F5BigNatPolicy connection statistics:

    tmctl -d blade fw_nat_rule_stat
    
    context_type context_name                          rule_name
    --------- ---------------------------------------  --------------------------
    virtual   cnf-cnf-context-secure-SecureContext_vs  10-20-subnet-natpolicyrule
    
    micro_rules counter last_hit_time action
    ----------- ------- ------------- ------
              1       8    1643836695      0
    
    tmctl -d blade fw_nat_trans_stat -s type,name,translation_requests
    
    type         name        translation_requests
    ------------ ----------- --------------------
    fw_src_trans transparent                    8
    fw_dst_trans transparent                    8
    fw_src_trans automap                        0
    
  3. Verify the F5BigNatPolicy client IP address mappings:

    lsndb list all
    
    Client                                          Connections
    -----------------------------------------------------------
    0 client with 0 connection found.
    LSN Persistence Entries
    Client                                          Translation
    -----------------------------------------------------------
    10.20.2.220:52110                           10.200.2.8:8265
    10.20.2.220                                 10.200.2.8
    2 persist entries found.
    LSN port block allocations
    Client                                          Port block
    ----------------------------------------------------------
    0 port block entries found.
    LSN Inbound Mapping Entries
    Translation                                         Client
    ----------------------------------------------------------
    10.200.2.8:8265                          10.20.2.220:52110
    10.200.2.7:8397                          10.20.2.220:52106
    
  4. Verify the F5BigFwPolicy statistics:

    tmctl -d blade fw_rule_stat -s rule_name,counter,last_hit_time,action
    
    rule_name                  counter last_hit_time action
    -------------------------- ------- ------------- ------
    allow-4-firewallpolicyrule       1    1646355700      2
    allow-6-firewallpolicyrule       1    1646355702      2
    drop-4-firewallpolicyrule        0             0      0
    drop-6-firewallpolicyrule        0             0      0
    
  5. Verify the F5BigDnsApp DNS Profile statistics:

    tmctl -d blade profile_dns_stat -s name,queries,responses
    
    name                               queries responses
    ---------------------------------- ------- ---------
    cnf-gateway-cnf-dns-64-profile_dns      20        20
    
  6. Verify the F5BigContextSecure, and F5BigDnsApp virtual server statistics:

    tmctl -d blade virtual_server_stat -s name,clientside.tot_conns
    
    name                                   clientside.tot_conns
    -------------------------------------- --------------------
    cnf-gateway-ipv64-vip-SecureContext_vs                   15
    cnf-gateway-dns-64-virtual_server                        20
    

Feedback

Provide feedback to improve this document by emailing cnfdocs@f5.com.

Supplemental

  • Wikipedia NAT64 overvew.