EVPN MPLS Port-Based VLAN-Aware Bundle Service

In this article, we will review EVPN MPLS Port-Based VLAN-Aware Bundle Service  configuration example using Juniper MX devices. As per Port-Based VLAN-Aware service definition in RFC7432, all of the VLANs on the port are part of the same service and are mapped to a single bundle without any VID translation.

EVPN VLAN-Aware Bundle Service
EVPN VLAN-Aware Bundle Service

In our sample, we will add L3 IRB interfaces to VLANs, simulating L3 Default Gateways.
Continue reading “EVPN MPLS Port-Based VLAN-Aware Bundle Service”

MPLS VPN Service with Segment Routing

MPLS VPN Configuration example with IS-IS based Segment Routing (SPRING) on Juniper QFX5100 devices. The purpose of this lab is to demonstrate what LDP or RSVP-TE can be easily replaced with SR.

Complete Configuration Repository on GitHub:

https://github.com/bgphelp/blueprints/tree/master/SR/MPLS-VPN-SR-QFX5100

 
Continue reading “MPLS VPN Service with Segment Routing”

EVPN MPLS VLAN-Based Configuration

Configuration examples of VLAN-Based EVPN service using MPLS Dataplane Encapsulation in Segment Routing-Enabled Juniper Network.

Complete Configuration Repository on GitHub:

https://github.com/bgphelp/blueprints/tree/master/evpn/vlan-based-mx
Continue reading “EVPN MPLS VLAN-Based Configuration”

Segment Routing Cisco – Juniper Interop Design

Cisco and Juniper Segment Routing Interoperability design with configuration examples.  IS-IS based IGP topology.

Complete configuration repository on GitHub: https://github.com/bgphelp/blueprints/tree/master/1-SR-Cisco-Juniper

 

Continue reading “Segment Routing Cisco – Juniper Interop Design”

LDP to Segment Routing (also known as SR and SPRING) Migration Steps

Step-by-step migration from LDP-based design to Segment Routing topology in Juniper environment.  In this example, we will be using IS-IS as IGP protocol. 
Continue reading “LDP to Segment Routing (also known as SR and SPRING) Migration Steps”

Migrating to BGP-Free Core in Juniper Environment

Discussion on how to migrate to BGP-Free Core by deploying MPLS as network tunneling mechanism. Document provides step-by-step migration steps for a Juniper-based network.  
Continue reading “Migrating to BGP-Free Core in Juniper Environment”

Juniper High Availability Customer Site using AS-Prepend

Configuring Dual-CE BGP High Availability Site. This article provides Juniper Configuration Example that uses BGP AS-Prepend to identify primary and secondary paths.
Continue reading “Juniper High Availability Customer Site using AS-Prepend”

Cisco Configuration Blueprint – Single-Homed CE Device with EBGP

Introduction

In this example, we will show recommended configuration for a Single-homed Single CE device using private AS with an upstream ISP. It is assumed that management of this device will be performed from a dedicated server residing within Customer’s Network.

This type of setup is quite common in an environment where a dedicated firewall performing source NAT function is setup to protect customer infrastructure.

Cisco Single Homed CE
Cisco Single Homed CE

Please note, that the Management Station is connected directly to the LAN interface for illustration purpose only. In real production deployments, Management Station must be protected by a firewall.

BGP Configuration

BGP configuration can be split in the following tasks:

  • Accept the default route from the ISP while discarding all other advertisements that might be sent to your CE
  • Advertise your subnet (120.0.50.0/24) while making sure that no other routers are erroneously injected
  • Secure BGP session by configuring a MD5 key

The actual configuration is comprised of the following blocks:

  1. Configure Two prefix lists – one with the subnet you’ll advertise upstream and the other one with the default route you’ll be receiving from your ISP:
ip prefix-list default-only seq 10 permit 0.0.0.0/0

ip prefix-list originated-out seq 10 permit 120.0.50.0/24

 

  1. Configure BGP session with prefix-filtering and MD5 session protection
router bgp 111100

 bgp log-neighbor-changes

 network 120.0.50.0 mask 255.255.255.0

 neighbor 120.0.4.17 remote-as 100

 neighbor 120.0.4.17 description PE2

 neighbor 120.0.4.17 password 7 14141B180F0B

 neighbor 120.0.4.17 soft-reconfiguration inbound

 neighbor 120.0.4.17 prefix-list default-only in

 neighbor 120.0.4.17 prefix-list originated-out out

!

Securing the Router

Next step is to secure the router itself. But default, it will pass any traffic (with some exceptions, not covered in this article) and accept connections from anywhere on the Internet. Your job is to make sure that only trusted sources can communicate with your device (control plane protection) and spoofed traffic is not allowed in and out of your network (data plane protection).

Data Plane Protection

  1. Configure access-list to block spoofed traffic originated on the Internet:
ip access-list extended martians

 deny   ip host 255.255.255.255 any

 deny   ip 0.0.0.0 0.255.255.255 any

 deny   ip 127.0.0.0 0.255.255.255 any

 deny   ip 10.0.0.0 0.255.255.255 any

 deny   ip 172.16.0.0 0.15.255.255 any

 deny   ip 192.168.0.0 0.0.255.255 any

 deny   ip 196.18.0.0 10.1.255.255 any

 deny   ip 240.0.0.0 15.255.255.255 any

 deny   ip 224.0.0.0 15.255.255.255 any

 deny   ip 169.254.0.0 0.0.255.255 any

 deny   ip 192.0.0.0 0.255.255.255 any

 deny   ip 198.0.0.0 0.255.255.255 any

 deny   ip 203.0.0.0 0.255.255.255 any

 deny   ip 100.64.0.0 0.0.63.255 any

! ßLocal Traffic, should not be arriving from the Internet à 

 deny   ip 120.0.50.0 0.0.0.255 any

 permit ip any any
  1. Configure interface with security commands and uRPF on the LAN interface. Note that ‘no ip unreachables’ will block traceroute.
interface GigabitEthernet2

 description 'CE5->PE2'

 ip address 120.0.4.18 255.255.255.252

 no ip redirects

 no ip unreachables

 no ip proxy-arp

 ip access-group martians in

 negotiation auto

!

interface GigabitEthernet3

 description 'LAN Segment'

 ip address 120.0.50.1 255.255.255.0

 no ip redirects

 no ip unreachables

 no ip proxy-arp

 ip verify unicast source reachable-via rx

 negotiation auto

!

Control Plane Protection

  1. Configure Logging; Enable SSH and SNMP access-lists, disabled unnecessary services and protocols:
no ip http server

no ip http secure-server

ip route 192.168.74.0 255.255.255.0 192.168.3.18

ip ssh rsa keypair-name ssh-key

ip ssh version 2


logging host 120.0.50.10

access-list 10 permit 120.0.50.10

snmp-server community t0ps3crrr3t RO 10

line vty 0 4

 access-class 10 in

 exec-timeout 11 0

 password d0ntt3ll

 login local

 transport input ssh

!

 

  1. Configure Control Plane (CPP) Protection
! Routing Protocols (BGP)

access-list 120 permit tcp any gt 1024 host 120.0.4.18 eq bgp

access-list 120 permit tcp any eq bgp host 120.0.4.18 gt 1024 established



! Management Protocols (SSH, SNMP)

access-list 121 permit tcp host 120.0.50.10 host 120.0.50.1 eq 22

access-list 121 permit tcp host 120.0.50.10 eq 22 host 120.0.50.1 established

access-list 121 permit udp host 120.0.50.10 host 120.0.50.1 eq snmp



! Ping / Traceroute LAN Interface

access-list 122 permit icmp any host 120.0.50.1 echo

access-list 122 permit icmp any host 120.0.50.1 echo-reply

access-list 122 permit icmp any host 120.0.50.1 ttl-exceeded

access-list 122 permit icmp any host 120.0.50.1 packet-too-big

access-list 122 permit icmp any host 120.0.50.1 port-unreachable

access-list 122 permit icmp any host 120.0.50.1 unreachable



! Ping/Traceroute WAN Interface

access-list 122 permit icmp any host 120.0.4.18 echo

access-list 122 permit icmp any host 120.0.4.18 echo-reply

access-list 122 permit icmp any host 120.0.4.18 ttl-exceeded

access-list 122 permit icmp any host 120.0.4.18 packet-too-big

access-list 122 permit icmp any host 120.0.4.18 port-unreachable

access-list 122 permit icmp any host 120.0.4.18 unreachable


! Undesired Traffic

access-list 123 permit icmp any any fragments

access-list 123 permit udp any any fragments

access-list 123 permit tcp any any fragments

access-list 123 permit ip any any fragments

access-list 123 permit tcp any any eq bgp rst



! All Other Traffic

access-list 124 permit tcp any any

access-list 124 permit udp any any

access-list 124 permit icmp any any

access-list 124 permit ip any any

!



! Define Class-Maps

class-map match-all Catch-All-IP

 match access-group 124

class-map match-all Management

 match access-group 121

class-map match-all Normal

 match access-group 122

class-map match-all Undesirable

 match access-group 123

class-map match-all Routing

 match access-group 120

!



! Configure CoPP Policy

policy-map RTR_CoPP

 class Undesirable

  police 8000 1500 1500 conform-action drop  exceed-action drop

 class Routing

  police 100000 5000 5000 conform-action transmit  exceed-action transmit

 class Management

  police 100000 20000 20000 conform-action transmit  exceed-action drop

 class Normal

  police 50000 5000 5000 conform-action transmit  exceed-action drop

 class Catch-All-IP

  police 50000 5000 5000 conform-action transmit  exceed-action drop

 class class-default

  police 8000 1500 1500 conform-action transmit  exceed-action drop



! Apply CoPP Policy

control-plane

 service-policy input RTR_CoPP

!

Complete Router Configuration

service timestamps debug datetime localtime show-timezone

service timestamps log datetime localtime show-timezone

service password-encryption!

hostname CE11

!

boot-start-marker

boot-end-marker

!

!

enable secret 5 $1$9Ah6$7tFkcd/bJRrHSx0grfmYA1

!

no aaa new-model

no ip source-route




no ip domain lookup

!

username cisco privilege 15 secret 5 $1$ZJAP$Hmq/nCv7qQcwPHyB4Ixdo0

!

!

class-map match-all Catch-All-IP

 match access-group 124

class-map match-all Management

 match access-group 121

class-map match-all Normal

 match access-group 122

class-map match-all Undesirable

 match access-group 123

class-map match-all Routing

 match access-group 120

!

policy-map RTR_CoPP

 class Undesirable

  police 8000 1500 1500 conform-action drop  exceed-action drop

 class Routing

  police 100000 5000 5000 conform-action transmit  exceed-action transmit

 class Management

  police 100000 20000 20000 conform-action transmit  exceed-action drop

 class Normal

  police 50000 5000 5000 conform-action transmit  exceed-action drop

 class Catch-All-IP

  police 50000 5000 5000 conform-action transmit  exceed-action drop

 class class-default

  police 8000 1500 1500 conform-action transmit  exceed-action drop

!

!

interface GigabitEthernet1

 description 'Out-of-Band Management'

 ip address 192.168.3.231 255.255.255.0

 no ip redirects

 no ip unreachables

 no ip proxy-arp

 negotiation auto

!

interface GigabitEthernet2

 description 'CE5->PE2'

 ip address 120.0.4.18 255.255.255.252

 no ip redirects

 no ip proxy-arp

 ip access-group martians in

 negotiation auto

!

interface GigabitEthernet3

 description 'LAN Segment'

 ip address 120.0.50.1 255.255.255.0

 no ip redirects

 no ip unreachables

 no ip proxy-arp

 ip verify unicast source reachable-via rx

 negotiation auto

!

router bgp 111100

 bgp log-neighbor-changes

 network 120.0.50.0 mask 255.255.255.0

 neighbor 120.0.4.17 remote-as 100

 neighbor 120.0.4.17 description PE2

 neighbor 120.0.4.17 password 7 14141B180F0B

 neighbor 120.0.4.17 soft-reconfiguration inbound

 neighbor 120.0.4.17 prefix-list default-only in

 neighbor 120.0.4.17 prefix-list originated-out out

!

virtual-service csr_mgmt

!

ip forward-protocol nd

!

no ip http server

no ip http secure-server

ip route 192.168.74.0 255.255.255.0 192.168.3.18

ip ssh rsa keypair-name ssh-key

ip ssh version 2

!

ip access-list extended martians

 deny   ip host 255.255.255.255 any

 deny   ip 0.0.0.0 0.255.255.255 any

 deny   ip 127.0.0.0 0.255.255.255 any

 deny   ip 10.0.0.0 0.255.255.255 any

 deny   ip 172.16.0.0 0.15.255.255 any

 deny   ip 192.168.0.0 0.0.255.255 any

 deny   ip 196.18.0.0 10.1.255.255 any

 deny   ip 240.0.0.0 15.255.255.255 any

 deny   ip 224.0.0.0 15.255.255.255 any

 deny   ip 169.254.0.0 0.0.255.255 any

 deny   ip 192.0.0.0 0.255.255.255 any

 deny   ip 198.0.0.0 0.255.255.255 any

 deny   ip 203.0.0.0 0.255.255.255 any

 deny   ip 100.64.0.0 0.0.63.255 any

 deny   ip 120.0.50.0 0.0.0.255 any

 permit ip any any

!

!

ip prefix-list default-only seq 10 permit 0.0.0.0/0

!

ip prefix-list originated-out seq 10 permit 120.0.50.0/24

logging host 120.0.50.10

access-list 10 permit 120.0.50.10

access-list 10 permit 192.168.0.0 0.0.255.255

access-list 120 permit tcp any gt 1024 host 120.0.4.18 eq bgp

access-list 120 permit tcp any eq bgp host 120.0.4.18 gt 1024 established

access-list 121 permit tcp host 120.0.50.10 host 120.0.50.1 eq 22

access-list 121 permit tcp host 120.0.50.10 eq 22 host 120.0.50.1 established

access-list 121 permit udp host 120.0.50.10 host 120.0.50.1 eq snmp

access-list 122 permit icmp any host 120.0.50.1 echo

access-list 122 permit icmp any host 120.0.50.1 echo-reply

access-list 122 permit icmp any host 120.0.50.1 ttl-exceeded

access-list 122 permit icmp any host 120.0.50.1 packet-too-big

access-list 122 permit icmp any host 120.0.50.1 port-unreachable

access-list 122 permit icmp any host 120.0.50.1 unreachable

access-list 122 permit icmp any host 120.0.4.18 echo

access-list 122 permit icmp any host 120.0.4.18 echo-reply

access-list 122 permit icmp any host 120.0.4.18 ttl-exceeded

access-list 122 permit icmp any host 120.0.4.18 packet-too-big

access-list 122 permit icmp any host 120.0.4.18 port-unreachable

access-list 122 permit icmp any host 120.0.4.18 unreachable

access-list 124 permit tcp any any

access-list 124 permit udp any any

access-list 124 permit icmp any any

access-list 124 permit ip any any

!

snmp-server community t0ps3crrr3t RO 10

!

!

control-plane

 service-policy input RTR_CoPP

!

banner motd ^C

Disconnect IMMEDIATELY if you are not an authorized user!


^C

!

line con 0

 exec-timeout 11 0

 password d0ntt3ll

 stopbits 1

line vty 0 4

 access-class 10 in

 exec-timeout 11 0

 password d0ntt3ll

 login local

 transport input ssh

!

!

end

IPv4 Bogons

Introduction

BGP Best Practice Recommendation documented in RFC 7454 and discussed in “BGP Best Practices or Dissecting RFC 7454” article mandates the use of inbound prefix-list filtering to discard bogus route-advertisements to and from BGP peers. It is strongly recommended that you implement aforementioned filtering if you accept the full or partial BGP view from your peers.

You do not need to maintain inbound bogus route filtering if the only route you are planning to accept from your service providers is the default 0.0.0.0/0 prefix. In this scenario, you should configure an explicit prefix-filter permitting 0.0.0.0/0 route and rejecting all other advertisements.

Bogons, Martians, Bogus Advertisements

Over the years, networking professions have used various terms to refer to the same thing. These “bad” advertisements might be referred to as Bogons, Martian Lists, Bogus Advertisements, etc.

The current list is comprised of IP Blocks that are used for some kind of special use, such as RFC1918 space, Loopback block, etc. Sometime ago this list also included valid IPv4 prefixes that have not been allocated by The Internet Assigned Numbers Authority (IANA). IPv4 Space Exhaustion put stop to this. For the majority of ISPs and Enterprises, it is no longer feasible to include remaining unallocated blocks to the Bogons least, as this IPv4 space is small and constantly changing. The situation is very different when it comes to IPv6 space, and it will be discussed in IPv6 Martians article.

Importance of Bogons

The main reason for filtering-out Bogon advertisements is the Internet security. Bad things might begin to happen if you allow Bogon blocks to be accepted into your BGP domain. Let’s consider a few scenarios where hackers were able to advertise RFC1918 block to your network.

  • Firewall filters might consider RFC1918 blocks “trusted” space and permit dataflows that otherwise would be rejected
  • Spammers might send out email messages from servers in RFC1918 space, making it nearly impossible to track them back
  • Similar to Spam, DDoS Attacks from RFC1918 space are impossible to track
  • Your network might attract large volume of bogus traffic destined to RFC1918 space, such as portscans, vulnerability scans, etc

Current IPv4 Bogons List

Source: http://www.radb.net/query/?keywords=fltr-martian

  • 0.0.0/8
  • 10.0.0.0/8
  • 100.64.0.0/10
  • 127.0.0.0/8
  • 169.254.0.0/16
  • 172.16.0.0/12
  • 192.0.0.0/24
  • 192.0.2.0/24
  • 192.168.0.0/16
  • 198.18.0.0/15
  • 198.51.100.0/24
  • 203.0.113.0/24
  • 224.0.0.0/3

Cisco Configuration

ip prefix-list martians seq 10 deny 0.0.0.0/8 le 32

ip prefix-list martians seq 20 deny 10.0.0.0/8 le 32

ip prefix-list martians seq 30 deny 100.64.0.0/10 le 32

ip prefix-list martians seq 40 deny 127.0.0.0/8 le 32

ip prefix-list martians seq 50 deny 169.254.0.0/16 le 32

ip prefix-list martians seq 60 deny 172.16.0.0/12 le 32

ip prefix-list martians seq 70 deny 192.0.0.0/24 le 32

ip prefix-list martians seq 80 deny 192.0.2.0/24 le 32

ip prefix-list martians seq 90 deny 192.168.0.0/16 le 32

ip prefix-list martians seq 100 deny 198.18.0.0/15 le 32

ip prefix-list martians seq 110 deny 198.51.100.0/24 le 32

ip prefix-list martians seq 120 deny 203.0.113.0/24 le 32

ip prefix-list martians seq 130 deny 224.0.0.0/3 le 32

ip prefix-list martians seq 9999 permit 0.0.0.0/0 le 32




router bgp 111100

  ...

  neighbor 120.0.4.17 prefix-list martians in

 

Juniper Configuration

Set Format:

set policy-options policy-statement martians-ipv4  from route-filter 0.0.0.0/8 orlonger reject

set policy-options policy-statement martians-ipv4  from route-filter 10.0.0.0/8 orlonger reject

set policy-options policy-statement martians-ipv4  from route-filter 100.64.0.0/10 orlonger reject

set policy-options policy-statement martians-ipv4  from route-filter 127.0.0.0/8 orlonger reject

set policy-options policy-statement martians-ipv4  from route-filter 169.254.0.0/16 orlonger reject

set policy-options policy-statement martians-ipv4  from route-filter 172.16.0.0/12 orlonger reject

set policy-options policy-statement martians-ipv4  from route-filter 192.0.0.0/24 orlonger reject

set policy-options policy-statement martians-ipv4  from route-filter 192.0.2.0/24 orlonger reject

set policy-options policy-statement martians-ipv4  from route-filter 192.168.0.0/16 orlonger reject

set policy-options policy-statement martians-ipv4  from route-filter 198.18.0.0/15 orlonger reject

set policy-options policy-statement martians-ipv4  from route-filter 198.51.100.0/24 orlonger reject

set policy-options policy-statement martians-ipv4  from route-filter 203.0.113.0/24 orlonger reject

set policy-options policy-statement martians-ipv4  from route-filter 224.0.0.0/3 orlonger reject

set policy-options policy-statement martians-ipv4  then accept




set protocols bgp group ebgp import martians-ipv4

Curly Braces format:

policy-statement martians-ipv4 {
 from {
  route-filter 0.0.0.0/8 orlonger reject;
  route-filter 10.0.0.0/8 orlonger reject;
  route-filter 100.64.0.0/10 orlonger reject;
  route-filter 127.0.0.0/8 orlonger reject;
  route-filter 169.254.0.0/16 orlonger reject;
  route-filter 172.16.0.0/12 orlonger reject;
  route-filter 192.0.0.0/24 orlonger reject;
  route-filter 192.0.2.0/24 orlonger reject;
  route-filter 192.168.0.0/16 orlonger reject;
  route-filter 198.18.0.0/15 orlonger reject;
  route-filter 198.51.100.0/24 orlonger reject;
  route-filter 203.0.113.0/24 orlonger reject;
  route-filter 224.0.0.0/3 orlonger reject;
  }
 then accept;
}

protocols {
 bgp {
   group ebgp {
    import martians-ipv4;
    ...
   } 
 }
}