In
modern networks the need for differentiating certain types of traffic arise,
i.e. to allow certain traffic classes to be treated differently and to be
routed differently other than normal traffic
This
need arise from the criticality of traffic passing through network which
sometimes forces the network administrator to influence the pattern based on
the needs
MTR
(Multi-Topology Routing) gives the ability to network owners to perform service
differentiation through class based forwarding
Before
going further into details, what is the keyword topology means to start with? A
Topology is defined as a set of routers and links for which a separate routes
are calculated.
The
entire network where the usual routes are calculated is known as the base
topology. Any additional topology is knows as class specific topologies and
they are a subset of the base topology. Each class specific topology handles a
traffic and characterized by an independent set of NLRI (Network Layer
Reachability Information) that is used to maintain separate RIB and FIB which
gives the router the flexibility to perform route calculation and forwarding
for each topology independently.
Intermediate
System to Intermediate System is one of the dynamic routing protocols that
support MTR
We will
be using the below topology to demonstrate the feature
As can
be seen from the above diagram, we have a core network consists of 5 routers,
the networks of concern are the loopback 0 interface of R1 and the loopback 0
interface of R5
The
source of packets will be loopback 0 interface of R1 and the destination of
concern will be loopback 0 interface of R5
All
routers will be participating in the same area (49.0001) and all routers will
be in the level 2 domain (our focus is MTR not ISIS functionality and circuit
types)
Note: all link IP addressing scheme
will be using the 192.168.XY.0/24 (where X is the source router and Y is the
destination router), as well, only loopback interfaces are to be configured on
the target routers: R1 and R5
Configuration
R1:
router isis 1
net 49.0001.0000.0000.0001.00
is-type level-2-only
interface {}
ip router isis 1
R2:
router isis 1
net 49.0001.0000.0000.0002.00
is-type level-2-only
interface {}
ip router isis 1
R3:
router isis 1
net 49.0001.0000.0000.0003.00
is-type level-2-only
interface {}
ip router isis 1
R4:
router isis 1
net 49.0001.0000.0000.0004.00
is-type level-2-only
interface {}
ip router isis 1
R5:
router isis 1
net 49.0001.0000.0000.0005.00
is-type level-2-only
interface {}
ip
router isis 1
As can be seen from the below diagram,
there are two equal paths to reach from R1 loopback 0 interface and R5 loopback
0 interface
The
first route is through the path: R1 – R3 – R5 and the second one is through the
path: R1 – R3 – R5
Note: There is another path which is
through R1 – R2 – R4 – R5 but will be out of focus in this document
R1#sh ip route isis
Codes: L - local, C - connected,
S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O -
OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 -
OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF
external type 2
i - IS-IS, su - IS-IS summary, L1 -
IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate
default, U - per-user static route
o - ODR, P - periodic downloaded static
route, + - replicated route
Gateway of last resort is not set
5.0.0.0/32 is subnetted, 1 subnets
i L2 5.5.5.5 [115/30] via 192.168.13.3,
00:04:32, FastEthernet1/0
[115/30] via 192.168.12.2,
00:04:32, FastEthernet2/0
i L2 192.168.24.0/24 [115/20] via 192.168.12.2,
00:05:38, FastEthernet2/0
i L2 192.168.25.0/24 [115/20] via 192.168.12.2,
00:05:38, FastEthernet2/0
i L2 192.168.35.0/24 [115/20] via 192.168.13.3,
00:05:25, FastEthernet1/0
i L2 192.168.45.0/24 [115/30] via 192.168.13.3,
00:01:04, FastEthernet1/0
[115/30]
via 192.168.12.2, 00:01:04, FastEthernet2/0
R1#sh ip route 5.5.5.5
Routing entry for 5.5.5.5/32
Known via "isis", distance 115, metric 30, type level-2
Redistributing via isis 1
Last update from 192.168.13.3 on FastEthernet1/0, 00:11:48 ago
Routing Descriptor Blocks:
192.168.13.3, from 5.5.5.5, 00:11:48 ago,
via FastEthernet1/0
Route metric is 30, traffic share count
is 1
* 192.168.12.2, from 5.5.5.5, 00:11:48 ago, via FastEthernet2/0
Route metric is 30, traffic share count
is 1
R1#traceroute 5.5.5.5 source
loopback 0 numeric
Type escape sequence to abort.
Tracing the route to 5.5.5.5
1 192.168.12.2 48 msec
192.168.13.3 36 msec
192.168.12.2 16 msec
2 192.168.35.5 32 msec
192.168.25.5 40 msec
The
demonstration example will take two DSCP values into consideration (DSCP 46
which is the critical traffic usually representing voice and video traffic will
follow the path R1 – R3 – R5 and it will be part of the topology called
CRITICAL_TOP
The second topology
for which the DSCP 32 marked traffic usually representing real time traffic
denoted as telepresence in the coming diagram will be handled by the so called
topology NONCRITICAL_TOP
As depicted
in the topology , we will influence traffic marked with DSCP46 to use the path
R1 – R3 – R5 and the traffic marked with DSCP32 to use the path R1 – R2 – R4 –
R5
Each
traffic pattern will use its own topology which means independent forwarding
decision and separated RIB, FIB as will be demonstrated later
The word
class has been mentioned more than once previously, which means we have to mark
our traffic as it is coming inside our network, how we are going to classify?
Exactly: MQC
But
first let us create our new topologies apart from the original one: Base
topology
R1#show
topology
Topology Address Family
Associated VRF State
base ipv4 default UP
Topologies Definition:
global-address-family ipv4
topology CRITICAL_TOP
forward-base
topology NONCRITICAL_TOP
forward-base
R1#sh topology
Topology Address Family Associated VRF State
base ipv4 default UP
CRITICAL_TOP ipv4 default UP
NONCRITICAL_TOP ipv4 default UP
MTR Traffic Classification:
class-map match-any
CRITICAL_CLASS
match ip dscp 46
class-map match-any
NONCRITICAL_CLASS
match ip dscp 32
policy-map type class-routing
ipv4 unicast POLICY
class CRITICAL_CLASS
select-topology CRITICAL_TOP
class NONCRITICAL_CLASS
select-topology NONCRITICAL_TOP
global-address-family ipv4
topology CRITICAL_TOP
forward-base
topology NONCRITICAL_TOP
forward-base
service-policy type class-routing
POLICY
Note: Before proceeding, when trying
to trace route from the router to any destination, you will not see the
topology option
R1#traceroute ?
WORD Trace route to destination address or
hostname
appletalk AppleTalk Trace
clns ISO CLNS Trace
ip IP Trace
ipv6 IPv6 Trace
ipx IPX Trace
mpls MPLS LSP Trace
oldvines Vines Trace (Cisco)
vines Vines Trace (Banyan)
After defining the topologies
(regardless of the number) , you will be able to see it and execute the command
based on its parameters
R1#traceroute ?
WORD Trace route to
destination address or hostname
appletalk AppleTalk Trace
clns ISO CLNS Trace
ip IP Trace
ipv6 IPv6 Trace
ipx IPX Trace
mpls MPLS LSP Trace
oldvines Vines Trace (Cisco)
topology Select the topology
vines Vines Trace (Banyan)
As well, we now can execute many
commands related to a specific topology and one the command of concern is to
view the RIB using the most well know command show ip route associated with the
target topology:
R1#sh ip route topology
CRITICAL_TOP
Routing Table: CRITICAL_TOP
Codes: L - local, C - connected,
S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O -
OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 -
OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF
external type 2
i - IS-IS, su - IS-IS summary, L1 -
IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate
default, U - per-user static route
o - ODR, P - periodic downloaded static
route, + - replicated route
Gateway of last resort is not set
1.0.0.0/32 is subnetted, 1 subnets
C 1.1.1.1 is directly connected,
Loopback0
192.168.12.0/32 is subnetted, 1 subnets
L 192.168.12.1 is directly connected,
FastEthernet2/0
192.168.13.0/24 is variably subnetted, 2
subnets, 2 masks
C 192.168.13.0/24 is directly connected,
FastEthernet1/0
L 192.168.13.1/32 is directly connected,
FastEthernet1/0
As can be seen from the above output,
no ISIS routes have been installed yet. The reason for is that we still did not
integrate our new defined topologies to our IGP: ISIS. This will enable the
metrics for the defined topologies to be sent via LSPs
To accomplish this, we need to
access the router isis configuration mode and access the respective address-family:
IPv4 (knowing that MTR is still not support for the IPv6 address-family
R1(config)#router isis 1
R1(config-router)#address-family
ipv4
% Must enable wide metrics first
As can be seen from the above
output, we have to change the metric-style to wide in order to successfully
activate the feature (for more details about the isis metric-style, please
check the below link)
router isis 1
metric-style wide
address-family ipv4
topology CRITICAL_TOP tid 30
topology NONCRITICAL_TOP tid 40
Each topology must be assigned a
topology ID (tid) from a predefined range:
R1(config-router-af)#topology
CRITICAL_TOP tid ?
<5-4095> Routing topology
tid
Next, what have to be done is to
enable the topology instances on a per-interface basis (we will follow the
third diagram which clearly shows how the DSCP46 marked traffic is treated as
well the DSCP32 marked traffic)
R1:
interface Loopback0
topology ipv4 unicast
CRITICAL_TOP
topology ipv4 unicast
NONCRITICAL_TOP
interface FastEthernet1/0
topology ipv4 unicast
CRITICAL_TOP
isis metric 20
interface FastEthernet2/0
topology ipv4 unicast
NONCRITICAL_TOP
isis metric 30
R2:
interface FastEthernet1/0
topology ipv4 unicast
NONCRITICAL_TOP
isis metric 30
interface FastEthernet3/0
topology ipv4 unicast
NONCRITICAL_TOP
isis metric 30
R3:
interface FastEthernet1/0
topology ipv4 unicast
CRITICAL_TOP
isis metric 20
interface FastEthernet2/0
topology ipv4 unicast CRITICAL_TOP
isis metric 20
R4:
interface FastEthernet1/0
topology ipv4 unicast
NONCRITICAL_TOP
isis metric 30
interface FastEthernet2/0
topology ipv4 unicast
NONCRITICAL_TOP
isis metric 30
R5:
interface Loopback0
topology ipv4 unicast
CRITICAL_TOP
topology ipv4 unicast
NONCRITICAL_TOP
interface FastEthernet1/0
topology ipv4 unicast
CRITICAL_TOP
isis metric 20
interface FastEthernet3/0
topology ipv4 unicast
NONCRITICAL_TOP
isis metric 30
As we are concerned about the
loopback interfaces for both R1 and R5 and the traffic of interest is sourced
from R1 loopback 0 interface to R5 loopback 0 interface for different types of
traffic using the defined topologies , both topologies (in our example) have to
be enabled on these interfaces
Now, before doing the respective
tests to ensure the proper flow of data as defined, let us check the database
of our routing protocol
R1#show isis database detail
IS-IS Level-2 Link State
Database:
LSPID LSP Seq Num LSP Checksum
LSP Holdtime ATT/P/OL
R1.00-00 * 0x00000089 0xF481
1160 0/0/0
Area Address: 49.0001
Topology:
IPv4 (0x0)
TID 30 (0x1E)
TID 40 (0x28)
NLPID: 0xCC
Hostname: R1
IP Address: 1.1.1.1
Metric: 10 IS-Extended
R2.01
Metric: 10 IS-Extended
R3.01
Metric: 20 IS (MT-TID 30) R3.01
Metric: 30 IS (MT-TID 40) R2.01
Metric: 10 IP 1.1.1.1/32
Metric: 10 IP
192.168.12.0/24
Metric: 10 IP
192.168.13.0/24
Metric: 10 IP (MT-TID 30)
1.1.1.1/32
Metric: 20 IP (MT-TID 30)
192.168.13.0/24
Metric: 10 IP (MT-TID 40)
1.1.1.1/32
Metric: 30 IP (MT-TID 40)
192.168.12.0/24
R2.00-00 0x0000008A 0xC1ED
1181 0/0/0
Area Address: 49.0001
Topology: IPv4 (0x0)
TID 30 (0x1E)
TID 40 (0x28)
NLPID: 0xCC
Hostname: R2
IP Address: 192.168.24.2
Metric: 10 IS-Extended
R2.01
Metric: 10 IS-Extended
R4.01
Metric: 10 IS-Extended R5.03
Metric: 30 IS (MT-TID 40) R2.01
Metric: 30 IS (MT-TID 40) R4.01
Metric: 10 IP
192.168.12.0/24
Metric: 10 IP
192.168.24.0/24
Metric: 10 IP
192.168.25.0/24
Metric: 30 IP (MT-TID 40)
192.168.12.0/24
Metric: 30 IP (MT-TID 40)
192.168.24.0/24
R2.01-00 0x00000084 0x77CE
308 0/0/0
Metric: 0 IS-Extended
R2.00
Metric: 0 IS-Extended
R1.00
R3.00-00 0x00000088 0xA8D8
606 0/0/0
Area Address: 49.0001
Topology: IPv4 (0x0)
TID 30 (0x1E)
TID 40 (0x28)
NLPID: 0xCC
Hostname: R3
IP Address: 192.168.35.3
Metric: 10 IS-Extended
R3.01
Metric: 10 IS-Extended
R5.02
Metric: 20 IS (MT-TID 30)
R3.01
Metric: 20 IS (MT-TID 30)
R5.02
Metric: 10 IP
192.168.13.0/24
Metric: 10 IP
192.168.35.0/24
Metric: 20 IP (MT-TID 30)
192.168.13.0/24
Metric: 20 IP (MT-TID 30)
192.168.35.0/24
R3.01-00 0x00000085 0x76CC
947 0/0/0
Metric: 0 IS-Extended
R3.00
Metric: 0 IS-Extended
R1.00
R4.00-00 0x00000089 0xD739
647 0/0/0
Area Address: 49.0001
Topology: IPv4 (0x0)
TID 30 (0x1E)
TID 40 (0x28)
NLPID: 0xCC
Hostname: R4
IP Address: 192.168.45.4
Metric: 10 IS-Extended
R4.01
Metric: 10 IS-Extended
R5.04
Metric: 30 IS (MT-TID 40)
R4.01
Metric: 30 IS (MT-TID 40)
R5.04
Metric: 10 IP
192.168.24.0/24
Metric: 10 IP
192.168.45.0/24
Metric: 30 IP (MT-TID 40) 192.168.24.0/24
Metric: 30 IP (MT-TID 40)
192.168.45.0/24
R4.01-00 0x00000084 0x8DB3
648 0/0/0
Metric: 0 IS-Extended
R4.00
Metric: 0 IS-Extended
R2.00
R5.00-00 0x00000089 0x11D2
333 0/0/0
Area Address: 49.0001
Topology: IPv4 (0x0)
TID 30 (0x1E)
TID 40 (0x28)
NLPID: 0xCC
Hostname: R5
IP Address: 5.5.5.5
Metric: 10 IS-Extended
R5.04
Metric: 10 IS-Extended
R5.03
Metric: 10 IS-Extended
R5.02
Metric: 20 IS (MT-TID 30) R5.02
Metric: 30 IS (MT-TID 40) R5.04
Metric: 10 IP 5.5.5.5/32
Metric: 10 IP
192.168.25.0/24
Metric: 10 IP
192.168.35.0/24
Metric: 10 IP
192.168.45.0/24
Metric: 10 IP (MT-TID 30) 5.5.5.5/32
Metric: 20 IP (MT-TID 30)
192.168.35.0/24
Metric: 10 IP (MT-TID 40) 5.5.5.5/32
Metric: 30 IP (MT-TID 40)
192.168.45.0/24
R5.02-00 0x00000086 0x97A3
1004 0/0/0
Metric: 0 IS-Extended
R5.00
Metric: 0 IS-Extended
R3.00
R5.03-00 0x00000085 0x7EBD
1127 0/0/0
Metric: 0 IS-Extended
R5.00
Metric: 0 IS-Extended
R2.00
R5.04-00 0x00000083 0xA397
445 0/0/0
Metric: 0 IS-Extended
R5.00
Metric: 0 IS-Extended
R4.00
As can be seen, all parameters
defined (such as tid and metric are shown in this output), as well, we can be
more precise in choosing the topology of concern
R1#show isis database detail
topology CRITICAL_TOP
IS-IS Level-2 Link State
Database:
LSPID LSP Seq Num LSP Checksum
LSP Holdtime ATT/P/OL
R1.00-00 * 0x00000089 0xF481
1070 0/0/0
Area Address: 49.0001
Topology: TID 30 (0x1E)
NLPID: 0xCC
Hostname: R1
IP Address: 1.1.1.1
Metric: 20 IS (MT-TID 30)
R3.01
Metric: 10 IP (MT-TID 30)
1.1.1.1/32
Metric: 20 IP (MT-TID 30)
192.168.13.0/24
R2.00-00 0x0000008A 0xC1ED
1092 0/0/0
Area Address: 49.0001
Topology: TID 30 (0x1E)
NLPID: 0xCC
Hostname: R2
IP Address: 192.168.24.2
R2.01-00 0x00000085 0x75CF
1117 0/0/0
R3.00-00 0x00000088 0xA8D8
517 0/0/0
Area Address: 49.0001
Topology: TID 30 (0x1E)
NLPID: 0xCC
Hostname: R3
IP Address: 192.168.35.3
Metric: 20 IS (MT-TID 30)
R3.01
Metric: 20 IS (MT-TID 30)
R5.02
Metric: 20 IP (MT-TID 30)
192.168.13.0/24
Metric: 20 IP (MT-TID 30)
192.168.35.0/24
R3.01-00 0x00000085 0x76CC
858 0/0/0
R4.00-00 0x00000089 0xD739
558 0/0/0
Area Address: 49.0001
Topology: TID 30 (0x1E)
NLPID: 0xCC
Hostname: R4
IP Address: 192.168.45.4
R4.01-00 0x00000084 0x8DB3
559 0/0/0
R5.00-00 0x0000008A 0x0FD3
1119 0/0/0
Area Address: 49.0001
Topology: TID 30 (0x1E)
NLPID: 0xCC
Hostname: R5
IP Address: 5.5.5.5
Metric: 20 IS (MT-TID 30)
R5.02
Metric: 10 IP (MT-TID 30)
5.5.5.5/32
Metric: 20 IP (MT-TID 30)
192.168.35.0/24
R5.02-00 0x00000086 0x97A3
914 0/0/0
R5.03-00 0x00000085 0x7EBD
1036 0/0/0
R5.04-00 0x00000083 0xA397
355 0/0/0
Let us check the RIB for a
specific topology compared to the global routing table:
R1# sh ip route topology CRITICAL_TOP
Routing Table: CRITICAL_TOP
Codes: L - local, C - connected,
S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O -
OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 -
OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF
external type 2
i - IS-IS, su - IS-IS summary, L1 -
IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate
default, U - per-user static route
o - ODR, P - periodic downloaded static route,
+ - replicated route
Gateway of last resort is not set
1.0.0.0/32 is subnetted, 1 subnets
C 1.1.1.1 is directly connected,
Loopback0
5.0.0.0/32 is subnetted, 1 subnets
i L2 5.5.5.5 [115/50] via 192.168.13.3, 1d02h,
FastEthernet1/0
192.168.12.0/32 is subnetted, 1 subnets
L 192.168.12.1 is directly connected,
FastEthernet2/0
192.168.13.0/24 is variably subnetted, 2
subnets, 2 masks
C 192.168.13.0/24 is directly connected,
FastEthernet1/0
L 192.168.13.1/32 is directly connected,
FastEthernet1/0
i L2 192.168.35.0/24 [115/40] via 192.168.13.3,
1d02h, FastEthernet1/0
R1#show ip route
Codes: L - local, C - connected,
S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O -
OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 -
OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF
external type 2
i - IS-IS, su - IS-IS summary, L1 -
IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate
default, U - per-user static route
o - ODR, P - periodic downloaded static
route, + - replicated route
Gateway of last resort is not set
1.0.0.0/32 is subnetted, 1 subnets
C 1.1.1.1 is directly connected,
Loopback0
5.0.0.0/32 is subnetted, 1 subnets
i L2 5.5.5.5 [115/30] via 192.168.13.3, 1d02h,
FastEthernet1/0
[115/30] via 192.168.12.2,
1d02h, FastEthernet2/0
192.168.12.0/24 is variably subnetted, 2
subnets, 2 masks
C 192.168.12.0/24 is directly connected,
FastEthernet2/0
L 192.168.12.1/32 is directly connected,
FastEthernet2/0
192.168.13.0/24 is variably subnetted, 2
subnets, 2 masks
C 192.168.13.0/24 is directly connected,
FastEthernet1/0
L 192.168.13.1/32 is directly connected,
FastEthernet1/0
i L2 192.168.24.0/24 [115/20] via 192.168.12.2,
1d02h, FastEthernet2/0
i L2 192.168.25.0/24 [115/20] via 192.168.12.2,
1d02h, FastEthernet2/0
i L2 192.168.35.0/24 [115/20] via 192.168.13.3,
1d02h, FastEthernet1/0
i L2 192.168.45.0/24 [115/30] via 192.168.13.3,
1d02h, FastEthernet1/0
[115/30] via
192.168.12.2, 1d02h, FastEthernet2/0
R1#show ip route topology
CRITICAL_TOP 5.5.5.5
Routing Table: CRITICAL_TOP
Routing entry for 5.5.5.5/32
Known via "isis", distance 115, metric 50, type level-2
Redistributing via isis 1
Last update from 192.168.13.3 on FastEthernet1/0, 1d02h ago
Routing Descriptor Blocks:
* 192.168.13.3, from 5.5.5.5, 1d02h ago, via FastEthernet1/0
Route metric is 50, traffic share
count is 1
R1#show ip route topology
NONCRITICAL_TOP 5.5.5.5
Routing Table: NONCRITICAL_TOP
Routing entry for 5.5.5.5/32
Known via "isis", distance 115, metric 100, type level-2
Redistributing via isis 1
Last update from 192.168.12.2 on FastEthernet2/0, 1d02h ago
Routing Descriptor Blocks:
* 192.168.12.2, from 5.5.5.5, 1d02h ago, via FastEthernet2/0
Route metric is 100, traffic share
count is 1
Now, let us examine the traffic
flow for both DSCP values
R1#traceroute
Protocol [ip]:
Target IP address: 5.5.5.5
Source address: 1.1.1.1
DSCP Value [0]: 46
Numeric display [n]:
Timeout in seconds [3]:
Probe count [3]:
Minimum Time to Live [1]:
Maximum Time to Live [30]:
Port Number [33434]:
Loose, Strict, Record, Timestamp,
Verbose[none]:
Type escape sequence to abort.
Tracing the route to 5.5.5.5
1 192.168.13.3 16 msec 16 msec 20 msec
2 192.168.35.5 40 msec 20 msec *
R1#traceroute
Protocol [ip]:
Target IP address: 5.5.5.5
Source address: 1.1.1.1
DSCP Value [0]: 32
Numeric display [n]:
Timeout in seconds [3]:
Probe count [3]:
Minimum Time to Live [1]:
Maximum Time to Live [30]:
Port Number [33434]:
Loose, Strict, Record, Timestamp,
Verbose[none]:
Type escape sequence to abort.
Tracing the route to 5.5.5.5
1 192.168.12.2 24 msec 12 msec 8 msec
2 192.168.24.4 56 msec 28 msec 20 msec
3 192.168.45.5 64 msec 56 msec *
R1#traceroute
Protocol [ip]:
Target IP address: 5.5.5.5
Source address: 1.1.1.1
DSCP Value [0]:
Numeric display [n]:
Timeout in seconds [3]:
Probe count [3]:
Minimum Time to Live [1]:
Maximum Time to Live [30]:
Port Number [33434]:
Loose, Strict, Record, Timestamp,
Verbose[none]:
Type escape sequence to abort.
Tracing the route to 5.5.5.5
1 192.168.12.2 24 msec
192.168.13.3 12 msec
192.168.12.2 16 msec
2 192.168.35.5 28 msec
192.168.25.5 36 msec
192.168.35.5 32 msec
And all is working as expected
and packets are flowing through the determined paths
Design considerations:
When trying to apply this feature,
several aspects to be take into consideration (rather than the hardware) such
as:
·
Only IPv4 address-family traffic is supported
(Multicast as well, IPv6 not)
·
Many databases do exist now as we are creating
multiple topologies as well as RIB and FIB tables which could affect the
scalability and stability of network in case the devices already in low profile
in respect to memory and CPU
·
Adaptability is in place when using such a feature
as it allow the administrator to manipulate traffic as needed (utilizing the
links effectively)
·
No need for MPLS to be enabled in the network (when enabled,
some other features could be deployed such as MPLS TE)
·
Redundancy can be achieved for traffic as topology
could be used for some traffic and another topology could be used as a backup
for the same traffic
Brian Storming:
From: Network admin
To: Consultant
Dear
Hope this finds you well
I have decided to deploy MTR
within my ISIS backbone, and I have made up my mind to classify three types of
traffic: Voice, TP and Scavenger
As well, I have chosen the paths
that will carry the respective types of traffic as depicted in the network
diagram
What I am confused about is which
interfaces to be enabled for which topology?
Waiting your feedback
Thanks
BR,
Network Admin
