7 - InterVLAN_Routing SRX

Inter-VLAN Routing4-*
Inter-VLAN routing allows Layer 3 communications between individual subnets or VLANs
Typically performed at the distribution layer
Inter-VLAN communications require that interfaces be configured for Layer 3 operation
Protocol family determines layer of operation
[edit]
Logical Layer 3 VLAN interface (RVI)
*
AS1 (Layer 2)
AS2 (Layer 2)
Host A
*
Configure Layer 2 and Layer 3 VLAN interfaces:
[edit]
*
Associate Layer 3 VLAN interfaces with proper VLANs:
[edit]
}
*
EX-series switches support the following Layer 3 unicast forwarding mechanisms and protocols:
Static routing
Selects an active route to each destination
Populates the forwarding table
EX-series switches use the inet.0 routing table for IPv4 unicast routing
Direct
Routing
Table
Forwarding
Table
Routing
Protocol
Databases
Primary criterion for selecting the active route
Ranges from 0 to 4,294,967,295, with lower value preferred
Route Preference Values
Routing Information Source
170
user@switch> show route
inet.0: 6 destinations, 7 routes (6 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
10.1.1.0/24 *[Static/5] 00:10:24
MultiRecv
Route source and preference
*
Defined under [edit routing-options] hierarchy
Always require a configured next hop
Valid options are IP address, discard, and reject
Qualified next-hop option allows independent preference
user@switch> show route protocol static
0.0.0.0/0 *[Static/5] 00:01:07
Static Routing Case Study
Use static routing to provide connectivity among all connected subnets and loopback addresses
ge-0/0/10
.2
ge-0/0/2
.1
ge-0/0/2
.1
ge-0/0/10
.1
10.222.2.0/30
10.222.1.0/24
10.222.3.0/24
}
Create a default route on S1; use S2 as the next hop
Default and static routes are configured under the [edit routing-options] hierarchy level
A default route matches all destinations when a more specific route entry does not exist
ge-0/0/10
.2
ge-0/0/2
.1
ge-0/0/2
.1
ge-0/0/10
.1
10.222.2.0/30
10.222.1.0/24
10.222.3.0/24
}
Create static routes on S2; use S1 as the next hop
ge-0/0/10
.2
ge-0/0/2
.1
ge-0/0/2
.1
ge-0/0/10
.1
10.222.2.0/30
10.222.1.0/24
10.222.3.0/24
Default static route is active on S1
Test confirms
end-to-end routing
user@s1> show route protocol static
0.0.0.0/0 *[Static/5] 00:11:33
PING 10.222.3.1 (10.222.3.1): 56 data bytes
!!!!!!!!!!!!!!!!!!!!!!!!!
round-trip min/avg/max/stddev = 1.215/4.397/35.945/6.451 ms
OSPF is a link-state routing protocol that:
Reliably floods LSAs to distribute link-state information
Creates a complete database for the network
Uses the SPF algorithm to calculate best paths within a network
Uses areas to incorporate hierarchy and allow for scalability
Backbone
Area border router:
Any router that belongs to more than one area, ABRs connect OSPF areas to the OSPF backbone (Area 0)
Autonomous system boundary router:
Any router that injects routing information from outside the OSPF domain into the OSPF domain
Backbone
Single AS can be divided into smaller groups called areas
Areas can limit the size of the link-state database
Routers maintain identical databases within the same area
Area 0 distributes routing information between other areas
Interarea communications typically traverse the backbone (Area 0)
Backbone
*
Sample Single-Area OSPF Topology
Use a single OSPF area to provide connectivity among all connected subnets as well as loopback addresses
ge-0/0/11
.2
ge-0/0/0
.1
ge-0/0/0
.1
ge-0/0/11
.1
10.222.2.0/30
10.222.1.0/24
10.222.3.0/24
Use the show ospf neighbor command to display adjacencies
Use the detail or extensive keyword for added information
Use the clear ospf neighbor command to clear adjacencies
Specify individual neighbors or clear all neighbor adjacencies
user@s1> clear ospf neighbor ?
*
Monitoring OSPF (2 of 3)
Use the show ospf route command to display routes learned and advertised into OSPF
Includes routes for interfaces running OSPF
user@s1> show ospf route
Topology default Route Table:
Type Type Type Interface addr/label
192.168.36.1 Intra Router IP 1 ge-0/0/11.0 10.222.2.2
10.222.1.0/24 Intra Network IP 1 ge-0/0/0.0
10.222.2.0/24 Intra Network IP 1 ge-0/0/11.0
10.222.3.0/24 Intra Network IP 2 ge-0/0/11.0 10.222.2.2
192.168.24.1/32 Intra Network IP 0 lo0.0
192.168.36.1/32 Intra Network IP 1 ge-0/0/11.0 10.222.2.2
*
Monitoring OSPF (3 of 3)
Use the show ospf database command to display link-state database entries
Use the clear ospf database command to clear the link-state database
user@s1> show ospf database
Type ID Adv Rtr Seq Age Opt Cksum Len
Router *192.168.24.1 192.168.24.1 0x8000000e 1270 0x22 0xedcc 60
Router 192.168.36.1 192.168.36.1 0x8000000d 1271 0x22 0xd0c3 60
Network 10.222.2.2 192.168.36.1 0x8000000a 1271 0x22 0xb0f3 32
Self-originated LSAs marked with *
user@s1> clear ospf database
What Is VRRP?
An election protocol used to designate one of multiple VRRP routers as master
The master VRRP device assumes forwarding responsibilities for the LAN
Means of incorporating redundancy in a LAN
Typically used in high-availability Ethernet networks
Defined in RFC 2338
VRRP Terminology
Virtual router—Virtual entity that functions as the default router on a LAN; consists of a VRID and an IP address used as a gateway address known as the VIP address
VRRP router—Any router participating in VRRP, including the master and all backup routers
Master router—VRRP router performing packet forwarding and responding to ARP requests
*
Goals:
Provide a single gateway address on both S1 and S2 for the 10.10.1.0/24 subnet; this common gateway address should be bound to a Layer 3 VLAN interface for both S1 and S2
Use VRRP to provide redundancy during failure scenarios; S1 should function as the master during normal operations
ge-0/0/13
ge-0/0/5
.11./24
ge-0/0/16
.2/24
.3/24
.10/24
ge-0/0/5
S1
S2
Configuration on S1 and S2 to accomplish objectives
ge-0/0/13 {
Use the show vrrp command to view VRRP state information
Use the detail or extensive keywords for added details
user@s1> show vrrp
vip 10.10.1.1
vip 10.10.1.1
mas 10.10.1.2

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7 - InterVLAN_Routing SRX