Topology So, in this post we will cover the mtu and fragmentation cases. So, every interface/port have its capacity to send data across the line or port. So, the Maximum transfer unit (MTU). When I say MTU it usually means at layer 2 frame, but the actual data formation take place at layer 3. So,…
Gratuitous ARP is either request or reply packet that is needed in some cases. usually when we assigned any ip on interface or host boot the first packet it send is GARP. GARP packet have Sender and Target IP address same .Source mac address is of machine whereas destination mac is broadcast. GARP IMP Question…
TCP Header Format Total 13 Field Learn acronym HSDDDO Acche SE UR WINNER RE PAD FLAG—UPARSF
A route learned by one ibgp peer won’t be advertised to another ibgp peer. This is called BGP split horizon rule. This rule is used to avoid loop in ibgp cases. To mitigate this, we have following option by which one ibgp learned routes can be advertised to another ibgp peer. In this article we…
Topology Address resolution Protocol is used to find the Layer 2( mac address) information when the layer 3(IP) Information is already given. Total 9 filed in Header. The typical Address resolution protocol Header format is shown as below Fig1 ARP_Header
In this scenario router IOU1 already know the outgoing interface as we configured the ip route specifying the outgoing interface. So here IOU1 wil check the routing table and will get the outgoing interface detail in single lookup.
Since the network is Ethernet, the IOU1 must know the L2 address, so it will construct ARP packet having source IP address of PC1 and destination of 30.30.30.2. Source mac of IOU e0/1 interface and DMAC as 0.0.0.0.
OSI Stands for open system interconnection model. This is reference or virtual model, you cannot see it , touch it ,but its exists conceptually just like electron, protons etc. OSI model is invented by ISO(International standard organization). ISO is non profit organization that defines several standards. It is just like other standard e.g ISI mark,…
Topology Summary: To implement Flex VPN or IPSEC VPN the topology shown above. The motive is to make the reachability between LAN to LAN network i.e from 20.20.20.0 to 30.30.30.0 & vice versa. Currently we have configure simple connectivity in which R1 and R2 is reachable to each other via internet cloud. The basic requirement…
Topology Objectives Create Gre tunnel between Router A and Router c. We are creating tunnel to internal communication between two LAN segments without, advertising LAN IP in internet domain. Steps: Your end to end network should be reachable i.e the interface/node from where you are creating tunnel should reachable to destination interface/node. Here Router A…
Topology: Objective: To test the broken LSP failover using LDP protocol. All router in the topology are running under OSPF area 0.LDP has been enabled between them. Currently LDP synced and LDP neighbor ship has been established between all routers.
Topology: Objective: Configure MPLS L3VPN and understand it’s working. Currently PE1 & PE2 running iBGP under AS 100.PE1, P1, P2 & PE2 running OSPF as IGP. MPLS backbone running LDP for label distribution, LDP neighbor ship has been established among PE1, P1,P2 and PE2.CE1/CE11 using default routing towards PE1/PE2 respectively. MPLS VPN used two control…
Topology Objectives Use BGP attribute to influence the route selection in BGP. Currently Router R1/R1 running iBGP .Between R1-R3 & R2-R4 ebgp is used. Within ISP we have used Full iBGP mesh ( of course we could have used RR).Connect the network as shown in topology.
Topology Objectives Objective is to understand how bgp initialize when you enable interfaces and bgp parameters. We will check it by sniffing tool Wireshark to know what happening behind the scene. Wireshark will be enabled on f0/0 on R2.
Topology Objective: To implement BGP over GRE , the topology shown above. In topology R1 & R3 running BGP 100 whereas R2 running only IGP.R1-R4 & R3-R5 running ebgp and advertising prefix 4.4.4.4 and 5.5.5.5 respectively. R1-R2-R3 running ospf under area 0. Bgp over GRE can be configured in scenario where end to end BGP…