NETWORKING TUNNELS with Dynamic Routing Protocols on Juniper Devices

NETWORKING TUNNELS

*Network tunnel s typically bridge networks

*Traffic can be encrypted

*Examples of tunnel use includes:

 ​​ ​​ ​​ ​​ ​​ ​​ ​​​​ Hiding network traffic

 ​​ ​​ ​​ ​​ ​​ ​​ ​​​​ Providing dedudant ​​ links

 ​​ ​​ ​​ ​​ ​​ ​​ ​​​​ Sending non-IP over IP Networks

*Encapsulators and decapsulatiors are better known as tunnel endpoins

*Tunnel layers

Most networks utilize layer 3 tunnels across IP networks

Tunnels can also operate at layer 2

Layer 2 tunnel can send encapsulated frames across other layer2 tunnels

Ipv4 ve IPv6 connectivity destekliyor tunel islemi

Examples of Tunnel Usage

Tunnels have a varierty of applications

Examples: private ip addresses

Ipv4

Remote networks for connecting

Providing network redundancy

Proxy Services​​ Types​​ 

Local proxy ​​ server

Cloud Proxy services

Traditional proxy servers

Service are provided by Zsclaer,Virtela and Symantec

IP PROTOCOL NUMBERS

TCP ​​ : 6

UDP ​​ :17

ICMP ​​ :1

OSPF:89

EIGRP:88

For VPN traffic

AH ​​ :51

ESP : 50

GRE:47

IPv6​​ 41

MPLS​​ in IP :137

Lt2p: 115

TUNNEL TYPES in Junos

There are several types of tunnel

1-IP in IP​​ Tunnels

Use only ​​ ipv4 networks

Support TCP,UDP,ICMP and other IP protocols(ospf)

2-GRE​​ TUNNELS

Use ip protocol 47

Layer 3 traffic encapsulation within IP header

Support IP protocols, IPX,Apple talk,Decent ,CLNS and IPv6

Sifreleme yapilabilir 

The ecryption is known as​​ IPSec over GRE

MTU and TUNNELS

*IP packets minimum 20 bytes

*Maximum is 64Kb​​ 

Maximum Transmission Units (MTUs)

Default is 1500 bytes

If come over​​ packet size​​ , it will be​​ drop​​ 

Juniper has several recomandations about that:​​ 

*Set the MTU for a tunnel to 1524​​ 

*enable allow-fragmentation option

*enable clear-don`t -fregment option

*Use path MTU discovery

TUNNELS and DYNAMIC ROUTING PROTOCOLS

Tunnel ve routing protocols can use same time

Tunnels can send multicast traffic

Allows tunnels to OSPF hellos

Tunnels can also send RIP and BGP packets

These protocols make administration easier

They can have an adverse affect on tunnels

OSPF and TUNNEL

Configuration IP in IP Tunnels in Junos OS

At​​ SRX1​​ 

Has comminication between devices and after:

Edit interfaces ip-0/0/0.0

Set tunnel​​ source 192.51.100.1

Set family inet address 192.168.0.1/30

Top

Edit security zones security-zone TRUST

Set interfaces IP-0/0/0.0

Top

Edit protocols ospf

Set area 0.0.0.0 interface ip-0/0/0.0

Commit

At​​ SRX2

Edit interfaces ip-0/0/0.0

Set tunnel destination ​​ 192.51.100.1

Set tunnel source 203.0.113.2

Set family inet address 192.168.0.2/30

Top

Edit security zones security-zone TRUST

Set interfaces ip-0/0/0.0

Top

Edit protocols ospf

Set area 0.0.0.0 interface ip-0/0/0.0

Commit

For checking :

Show ospf neighbors

Show route protocols ospf

CONFIGURE GRE TUNNELS in JUNOS

At​​ SRX1

Edit interfaces gr-0/0/0.0

Set tunnel source 198.51.100.1

Set tunnel destination ​​ 203..0113.2

Set family inet address 192.168.0.1/30

Set clear-don’t-fragment-bit

Set family inet mtu 1524

Set tunnel ​​ allow-fragmentation

Set tunnel path-mtu-discovery

Set family iso

​​ top

Edit protocols isis

Set interface gr-0/0/0.0

Top

Edit security zones security-zone TRUST

Set interfaces ge-0/0/0.0

Commit

At​​ Srx2

Edit interfaces ge0-0/0/.0

Set tunnel source 203.0.113.2

Set tunnel destination 198.51.100.1

Set family inet address 192.168.0.2/30

Set clear-don’t-fragment-bit

Set family inet mmtu 1524

Set tunnel allow-fregmantation

Set tunnel path-mtu-discovery

Set family iso

Top edit protocols isis

Set interface ger-0//0/0.0

Top

Edit security zones security-zone TRUST

Set interfaces gr-0/0/0.0

Top

Commit

And ​​ after we can check :

Show isis adjcaceny

Show route protocol isis

Run show route isis

Troubleshooting on Tunnels

Show interface gr-0/0/0 brief

Show interface gr-0/0/0.0

Monitor interface ge-0/0/0.0

Monitor traffic interface gr-0/0/0.0

Monitor traffic interface gr-0/0/0.0 ​​ detail​​ 

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