A virtual PortChannel (vPC) allows links that are physically connected to two different Cisco Nexus™ 5000 Series devices to appear as a single PortChannel to a third device. The third device can be a Cisco Nexus 2000 Series Fabric Extender or a switch, server, or any other networking device. A vPC can provide Layer 2 multipathing, which allows you to create redundancy by increasing bandwidth, enabling multiple parallel paths between nodes and load-balancing traffic where alternative paths exist.

After you enable the vPC function, you create a peer keepalive link, which sends heartbeat messages between the two vPC peer devices.

The vPC domain includes both vPC peer devices, the vPC peer keepalive link, the vPC peer link, and all the PortChannels in the vPC domain connected to the downstream device. You can have only one vPC domain ID on each device.

• vPC Quick Configuration Guide
• Design and Best practices

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Setup:

• R1 functions as the internet.
• R2 is the first location with Public IP 1.1.1.2/30
• R3 is the second location with Public IP 1.1.2.2/30

There must be a GRE tunnel configured between R2 and R3 so that OSPF can be used between them. In the example we will use a tunnel with and without IPsec.

Configuration without IPsec:

ROUTER 2:

R2:

# WAN ADDRESS
interface FastEthernet0/0
 ip address 1.1.1.2 255.255.255.0
 duplex auto
 speed auto
!

# TUNNEL ADDRESS
interface Tunnel0
 ip address 10.10.10.1 255.255.255.252
 tunnel source 1.1.1.2
 tunnel destination 1.1.2.2
!

# LAN ADDRESS
interface Loopback0
 ip address 192.168.10.1 255.255.255.0
!

# OSPF CONFIG
router ospf 1
 log-adjacency-changes
 network 10.10.10.0 0.0.0.3 area 0
 network 192.168.10.0 0.0.0.255 area 0
!

# DEFAULT ROUTE (TRAFFIC TOWARDS R3)
ip route 0.0.0.0 0.0.0.0 1.1.1.1

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SNMP – Simple network management protocol

• Manager – Monitoring device
• Agent – Devices being monitored
• MIB – management information Base
• UDP port 161
• Uses GETs and SETs
• SNMP Traps
  • Agent informs the manager.
• SNMPv1 and 2c have community strings.
• SNMPv3 has encryption and authentication.
  • auth – Group using the AuthNoPriv Security Level
    • Authentication: yes
    • Privacy ( encryption ): no
  • noauth – Group using the noAuthNoPriv Security Level
    • Authentication: no
    • Privacy ( encryption ): no
  • Priv – Group using the AuthPriv Security Level
    • Authentication: yes
    • Privacy ( encryption ): yes
• If no read view is defined , all objects can be read.
• If no write view is defined , no objects can be written.
• If no notify view is defined , group members are not sent notifications.

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LAB III ( DMVPN, MGRE, NHRP, EIGRP)

• Point-to-multipoint layer 3 overlay VPN
• Logical hub and spoke topology
• Direct spoke to spoke is support

DMVPN uses a combination of:

• Multipoint GRE tunnels (mGRE)
• Next Hop Resolution Protocol ( NHRP )
• IPsec Crypto Profiles
• Routing

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• Virtual Private Network
  • Route exchange privacy
  • Path determination for packets
  • Data Security
    • IPSec IP security
  • Collection of standized protocols that provide
    • Confidentiality
    • Integrity
    • Authentication
    • Anti-Reply

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• Transition technique designed to allow native IPv6 hosts to access IPv4-only content.
  • (Translation technique not a tunneling technique).
• Primarily used to allow v6 hosts to initiate connections to IPv4 content.
  • Mechanisms do exist to allow the reverse.
• Stateful and stateless versions.
  • stateful can use any prefix
  • stateless has restriction on prefix

NAT64 and DNS64 co-existance.

1. IPv6 host sends AAAA DNS Query
2. DNS64 server tries AAAA lookup and fails
3. DNS64 server successfully resolves IPv4 address
4. DNS64 server generates AAAA DNS response of <IPv6 prefix:IPv4 adress> and sends it back to the client.

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• point-to-point tunnels
• MCT ( manually configured tunnel )
• GRE ( Generic Routing Encapsulation )

• Virtual point-to-point between two IPv4 routers
• IPv6 iGP routing protocols can run over these virtual links.

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• PBR intercepts packets before regular routing
• PBR overwrites the router’s natural destination
• PBR is tied to route-maps
  • Define the match criteria
  • Define the action for the packets
•  Packet forwarding
  • Outgoing interface
  • IP Next-Hop

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• Can be used by various
  • PBR
  • Static route
  • HSRP
• Feature to monitor destination
  • Cpu creates data to monitor
  • Operations
    • ICMP, RTP, TCP, UDP, DNS, DHCP, HTTP, FTP
  • Different operations can be monitored at the same time
• The receiver can be a router or host
  • Might be configured as a SLA Responder

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