iLab Static routing Minoo Rouhi rouhi@net.in.tum.de Slides by - - PowerPoint PPT Presentation

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Jul 08, 2023 268 likes •556 views

iLab Static routing Minoo Rouhi rouhi@net.in.tum.de Slides by Benjamin Hof hof@in.tum.de Chair of Network Architectures and Services Department of Informatics Technical University of Munich Lab 2 17ws 1 / 21 Outline Meta

SLIDE 1

iLab

Static routing Minoo Rouhi rouhi@net.in.tum.de Slides by Benjamin Hof hof@in.tum.de

Chair of Network Architectures and Services Department of Informatics Technical University of Munich

Lab 2 – 17ws

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SLIDE 2

Outline

Meta Hierarchical addressing Routing decision Autoconfiguration

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SLIDE 3

Outline

Meta Hierarchical addressing Routing decision Autoconfiguration

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SLIDE 4

Recordings

◮ check that you can log in ◮ slides are with the videos (media portal) ◮ slides one day before the lecture (e-learning system) 4 / 21

SLIDE 5

First lab

Reminder:

◮ first deadline on Sunday ◮ free slots on all days but Tuesday and Wednesday

Your answers:

◮ understandable ◮ precise ◮ (concise) ◮ details: exhaustively cover the question

Use the feedback from the correction.

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SLIDE 6

Outline

Meta Hierarchical addressing Routing decision Autoconfiguration

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SLIDE 7

Address hierarchy

border router building 1 building 2 floor 1 building 2 floor 2

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SLIDE 8

Forwarding ./ routing

◮ routers operate on network layer ◮ forwarding is the distribution of data packets ◮ routing is the selection of the best path ◮ data/forwarding plane: packet forwarding ◮ control plane: create routing table ◮ management plane: administration (SSH, . . . ) ◮ routing information base ◮ forwarding information base 8 / 21

SLIDE 9

Internet protocol addresses

Example

2001:db8::1 0010 0000 0000 0001 0000 1101 1011 1000 . . . 0000 0001 20 01 0d b8 :: 01 11 × 0x00

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SLIDE 10

Internet protocol addresses

Example

2001:db8::1 0010 0000 0000 0001 0000 1101 1011 1000 . . . 0000 0001 20 01 0d b8 :: 01 11 × 0x00

Example

set of addresses: 2001:db8::/40 0010 0000 0000 0001 0000 1101 1011 1000 0000 0000 . . . 20 01 0d b8 00 /40 11 × 0x00

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SLIDE 11

Classless inter-domain routing (CIDR)

Example

2001:db8::/40

◮ most significant 40 bits identify network ◮ rest identifies hosts ◮ rest can be split up, e.g. use 3 /64 networks 10 / 21

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Example: CIDR

2001:db8::/40 2001:db8:0:1::/64 2001:db8:0:2::/64 2001:db8:0:3::/64

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SLIDE 13

Routing table (incomplete)

port network

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SLIDE 14

Routing table (incomplete)

port network 1 2001:db8:0:1::/64

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Routing table (incomplete)

port network 1 2001:db8:0:1::/64 2 2001:db8:0:2::/64

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SLIDE 16

Routing table (incomplete)

port network 1 2001:db8:0:1::/64 2 2001:db8:0:2::/64 2 2001:db8:0:3::/64

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SLIDE 17

Routing table (incomplete)

port network 1 2001:db8:0:1::/64 2 2001:db8:0:2::/64 2 2001:db8:0:3::/64 3 –

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SLIDE 18

Routing table (incomplete)

port network 1 2001:db8:0:1::/64 2 2001:db8:0:2::/64 2 2001:db8:0:3::/64 3 – 4

therwise

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SLIDE 19

Outline

Meta Hierarchical addressing Routing decision Autoconfiguration

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SLIDE 20

Longest prefix matching

◮ check for identity up to prefix length ◮ check if longer prefix also matches ◮ longest common prefix wins

Example

1 198.51.100.0/24 2 198.51.100.0/26

What happens with:

1. 198.51.100.10
2. 198.51.100.70
3. 203.0.113.2

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SLIDE 21

Forwarding information base

1 default dev eth0 via 192.0.2.1 2 192.0.2.0/30 dev eth0 3 198.51.100.0/24 dev eth1 via 198.51.100.130 4 203.0.113.0/24 dev eth1 via 198.51.100.130 5 198.51.100.128/30 dev eth1 6 203.0.113.240/28 dev eth2

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SLIDE 22

Neighbour discovery and routing

B A C β α θ γ δ D ǫ

1. What is our address?
2. What is the next hop?
3. What MAC address does the router have?

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SLIDE 23

Outline

Meta Hierarchical addressing Routing decision Autoconfiguration

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SLIDE 24

Address types

◮ unspecified: ::/128 ◮ loopback: ::1/128 ◮ multicast: ff00::/8 ◮ link local: fe80::/10 ◮ global: almost all the rest 18 / 21

SLIDE 25

Stateless address autoconfiguration in IPv6

node dst: solicited-node ff02::1:ff00:0/104 dst: all-routers ff02::2 router link-local IP global IP NS: DAD RS RA: prefix info NS: DAD

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SLIDE 26

SLAAC recap

1. link local address: fe80:: + modified EUI64 derived from MAC;
ther methods possible
2. duplicate address detection with neighbour solicitation to

solicited-nodes

3. router solicitation to all-routers
4. router advertisement

◮ managed address ◮ other configuration ◮ prefix information ◮ lifetime ◮ autonomous flag ◮ prefix

5. generate global IP
6. DAD

Requires /64.

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SLIDE 27