CCIE SEC General Networking

Basics
1. Have you tried switching it off & on again?
OSI Layers
1. Application
  1. Layer 7
  2. SMTP
  3. HTTP
2. Presenetation
  1. Layer 6
  2. XML / HTML
  3. GIF / JPEG
3. Session
  1. Layer 5
  2. Controls Connections... i.e. source port to destination port.. and source port tied to applications
4. Transport
  1. Layer 4
  2. TCP
  3. UDP
  4. ICMP
5. Network
  1. Layer 3
  2. Logical Addressing
  3. IP
  4. Routing
6. Data-Link
  1. Layer 2
  2. MAC Addresses
  3. ARP
  4. Switching
7. Physical
  1. Layer 1
  2. Physical Connections, plugs
  3. Fibre / Copper
TCP/IP Protocols
1. ICMP
  1. Protocol 1
  2. Types
    1. 0 Echo Reply
    2. 3 Destination Unreachable
    3. 4 Source Quench
    4. 5 Redirect
    5. 8 Echo Request
    6. 11 TTL Expired
2. TCP
  1. Protocol 6
  2. Connection-Orientated
3. UDP
  1. Protocol 17
  2. Connection LESS
4. IP v4
  1. Class A
  2. Class B
  3. Class C
  4. Class D
    1. MultiCast
  5. Class E
    1. Experimental
  6. RFC 1918
  7. RFC 2827
5. IP v6
Switching
1. VTP
  1. Modes
    1. Server
      1. DEFAULT!
    2. Client
    3. Transparent
      1. All VLANS are local
  2. Layer 2 Frames
  3. Domains
    1. Revision Number
      1. To re-Set to 0
        Change Domain Name
        Change Switch Mode
    2. VLANS in domain
    3. Paramaters
      1. Mode
        Version 2
        Version 2
      2. Pruning
2. VLANS
3. Spanning Tree
  1. BPDU
    1. Notication Frames
      1. Note Generated by spanning-tree portfast
    2. Config Frames
    3. Set with Source Mac & root bridge MAC
  2. Security
    1. Root Gurad
      1. Stops new root Bridge BPDUs, allows switches to connect
    2. BPDU Guard
      1. Rejects ANY BPDU
    3. Loop Gurad
      1. Stops Loops forming if no BPDU recieved
    4. UDLC
      1. UNI-Directional Loop Detection
      2. used to detect if tx or rx breaks
        Normal Mode = Log
        Aggressive Mode = Err_Disable Port
    5. BPDU Filter
      1. Filters Outbound BPDU
4. Trunking
Routing Protocols
1. RIP
  1. Distance Vector
  2. UDP 520
  3. Admin Distance 120
  4. Load Balance upto 16 paths
  5. Version 1
    1. Broadcast Updates
    2. Classfull
    3. No Authentication
  6. Version 2
    1. Classless, VLSM = ok!
    2. Auto Summary on Class
    3. MULTICAST - 224.0.0.8
    4. Authentication
2. EIGRP
  1. Admin Distance 90
3. IGRP
  1. Admin Distance 100
4. OSPF
  1. Admin Distance 110
  2. Multicast
    1. 224.0.0.5 (all SPF/link state routers, also known as AllSPFRouters)
    2. 224.0.0.6 (all Designated Routers, AllDRouters)
  3. OSPF does not use TCP or UDP but uses IP directly, via IP protocol 89
  4. Open Shortest Path First
  5. Classless, VLSM = ok!
  6. Link-State Routing Protocol
  7. LSA
    1. Link State Announcement
      1. Types
        LSA 1
        LSA 2
        LSA3
  8. IGP (Interior gateway protocol)
  9. All Areas must connect to Area 0
    1. Virtual Link can create a temp link to area 0
    2. Area 0 is the backbone area
  10. Stub Area
    1. A stub area is an area which does not receive external routes except the default route
  11. Configuring OSPF Authentication on a Virtual Link
    r3.3.3.3# debug ip ospf adj 23:48:06: OSPF: Interface OSPF_VL1 going Up 23:48:06: OSPF: Send with youngest Key 0 23:48:07: OSPF: Build router LSA for area 0, router ID 3.3.3.3, seq 0x80000001 23:48:07: OSPF: Build router LSA for area 2, router ID 3.3.3.3, seq 0x80000033 23:48:07: OSPF: Build router LSA for area 1, router ID 3.3.3.3, seq 0x80000030 23:48:14: OSPF: 2 Way Communication to 1.1.1.1 on OSPF_VL1, state 2WAY 23:48:14: OSPF: Send DBD to 1.1.1.1 on OSPF_VL1 seq 0x1EA opt 0x62 flag 0x7 len32 23:48:14: OSPF: Send with youngest Key 1 23:48:14: OSPF: Rcv DBD from 1.1.1.1 on OSPF_VL1 seq 0x3FB opt 0x62 flag 0x7 len 32 mtu 0 state EXSTART 23:48:14: OSPF: First DBD and we are not SLAVE 23:48:16: OSPF: Send with youngest Key 1 23:48:19: OSPF: Send DBD to 1.1.1.1 on OSPF_VL1 seq 0x1EA opt 0x62 flag 0x7 len 32 23:48:19: OSPF: Send with youngest Key 1 23:48:19: OSPF: Retransmitting DBD to 1.1.1.1 on OSPF_VL1 [1] 23:48:19: OSPF: Rcv DBD from 1.1.1.1 on OSPF_VL1 seq 0x3FB opt 0x62 flag 0x7 len 32 mtu 0 state EXSTART 23:48:19: OSPF: First DBD and we are not SLAVE 23:48:19: OSPF: Rcv DBD from 1.1.1.1 on OSPF_VL1 seq 0x1EA opt 0x62 flag 0x2 len 172 mtu 0 state EXSTART 23:48:19: OSPF: NBR Negotiation Done. We are the MASTER 23:48:19: OSPF: Send DBD to 1.1.1.1 on OSPF_VL1 seq 0x1EB opt 0x62 flag 0x3 len 112 23:48:19: OSPF: Send with youngest Key 1 23:48:19: OSPF: Send with youngest Key 1 23:48:19: OSPF: Database request to 1.1.1.1 23:48:19: OSPF: sent LS REQ packet to 5.0.0.1, length 48 23:48:19: OSPF: Rcv DBD from 1.1.1.1 on OSPF_VL1 seq 0x1EB opt 0x62 flag 0x0 len 32 mtu 0 state EXCHANGE 23:48:19: OSPF: Send DBD to 1.1.1.1 on OSPF_VL1 seq 0x1EC opt 0x62 flag 0x1 len 32 23:48:19: OSPF: Send with youngest Key 1 23:48:19: OSPF: Build router LSA for area 0, router ID 3.3.3.3, seq 0x80000030 23:48:19: OSPF: Rcv DBD from 1.1.1.1 on OSPF_VL1 seq 0x1EC opt 0x62 flag 0x0 len 32 mtu 0 state EXCHANGE 23:48:19: OSPF: Exchange Done with 1.1.1.1 on OSPF_VL1 23:48:19: OSPF: Synchronized with 1.1.1.1 on OSPF_VL1, state FULL !--- This indicates the establishment of neighbor adjacency. 23:48:19: %OSPF-5-ADJCHG: Process 2, Nbr 1.1.1.1 on OSPF_VL1 from LOADING to FULL, Loading Done
    1. ip ospf authentication-key cisco
    2. area 1 virtual-link 3.3.3.3 authentication-key cisco
  12. Sample Configuration for Authentication in OSPF
    1. Types
      1. Null Authentication
      2. Plain Text Authentication
      3. MD5 Authentication
    2. show ip ospf interface serial0
      R1-2503# show ip ospf interface serial0 Serial0 is up, line protocol is up Internet Address 192.16.64.1/24, Area 0 Process ID 10, Router ID 172.16.10.36 , Network Type POINT_TO_POINT, Cost: 64 Transmit Delay is 1 sec, State POINT_TO_POINT, Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Hello due in 00:00:05 Index 2/2, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 1, maximum is 1 Last flood scan time is 0 msec, maximum is 4 msec Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 70.70.70.70 Suppress hello for 0 neighbor(s) Message digest authentication enabled Youngest key id is 1
5. BGP
  1. TCP 179
IP Multicast