What topics 3.4 and 3.5 ask for
On the v1.1 blueprint, topic 3.4 covers single-area OSPFv2: how neighbor adjacencies form, the point-to-point and broadcast network types, DR and BDR selection, and the router ID. Topic 3.5 stays at concept level: what FHRPs are for, how they work and the vocabulary around them. There is no FHRP configuration item on v1.1 (Cisco’s v1.1 exam topics, checked October 29, 2026).
Cisco weights the whole IP Connectivity domain at 25% and does not split it by topic. The roughly 10% printed above this page is our estimate: we divide the 25% evenly across the domain’s five numbered topics, and this study area holds two of them.
Single area keeps the scope tight. Configuration work happens in Area 0, so area design, summarization and stub variants stay off the list. The vocabulary of a multi-area design, the router roles and route codes found at area boundaries, still turns up as recognition material, which is why a little of it appears in the frames below.
How it connects to the rest of the map
OSPF feeds the table that the routing table and static routes area teaches you to read; its routes arrive with an administrative distance of 110, a number worth comparing against static routes on the administrative distance vs metric page. On the LAN side, the FHRP virtual address is the gateway that DHCP hands to every host, which makes NAT, DHCP and DNS the natural next stop on the route.
Where the router ID comes from
- 0000 set by hand under the OSPF process
- 0010 used when no manual ID exists
- 0020 used when no loopback is up
HSRP, VRRP and GLBP side by side
| Point of comparison | HSRP | VRRP | GLBP |
|---|---|---|---|
| Standard (differs) | Cisco; RFC 2281 is informational | IETF standard, RFC 9568 (replaced RFC 5798) | Cisco proprietary |
| Router roles (differs) | Active and standby | Master and backup | One AVG, several AVFs |
| Default priority | 100 | 100 | 100 |
| Preemption by default (differs) | Off | On | Off for the AVG role |
| Virtual IP can be a real interface IP (differs) | No | Yes, on the owner router | No |
| Load sharing inside one group (differs) | No, one active router | No, one master | Yes, hosts are spread across AVFs |
| Named in v2.0 topic 3.4 (differs) | Yes | Yes | No |
≠ marks rows where at least two of the three differ.
RFC sources: RFC 2281 and RFC 9568. Which of the three to pick for a given design, and the traps in the role names, are worked through on HSRP vs VRRP vs GLBP.
The show commands and what each one answers
| Command | What it answers | Read this column first |
|---|---|---|
show ip ospf interface brief | Which interfaces run OSPF, in which area, with what cost | State: the interface’s role on its segment |
show ip ospf interface g0/0 | Network type, priority, timers and the DR and BDR addresses on one link | Network type and priority, the two settings behind any election |
show ip protocols | Router ID, the interfaces or networks OSPF covers, passive interfaces, distance | Passive interfaces, the quiet cause of a missing neighbor |
show standby brief | HSRP group, priority, preempt flag, state, active and standby routers, virtual IP | The P column: blank means preemption is off |
show vrrp brief | VRRP group, priority, owner flag, preempt, state and master address | State and master address together |
Cisco’s technote on show ip ospf interface walks through every field of that output.
Where this lands in v2.0
In the v2.0 exam topics (when v2.0 takes over), this material becomes topic 3.3, which adds OSPFv3 beside OSPFv2 (still one area, authentication excluded), and topic 3.4, which asks you to interpret HSRP and VRRP status. GLBP is no longer named.
OSPFv3 (RFC 5340) carries IPv6 prefixes but keeps a 32-bit router ID, so a router with no IPv4 address at all needs that ID set manually before the process will start.
Interpreting status means reading output like the last two rows of the table above: which router is active or master, at what priority, and whether it will give the role back. Practicing that reading now serves both versions.
Frames: OSPF & FHRP
Answer a frame and its notes open, including the reason each rejected option loses. To mix this area with the rest of the blueprint, run the practice test filtered to OSPF and FHRP.
Practice frames written by our editors for study, not Cisco items. The 200-301 exam itself mixes multiple choice, drag-and-drop and lab-style items.
Frame 001 of 018 · 0 answered · 0 ok
Keys
1–5 or A–E pick an option (on choose-N frames they toggle; then Check answer) · ← → previous / next frame · ↑ ↓ move in the frame list
- Frame 001 of 018
What OSPF network type should be configured on an interface when there are only two routers connected on a broadcast medium and you want to eliminate the DR/BDR election process?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Broadcast is the default on Ethernet, and it is the network type that runs the DR/BDR election.
Note on B
Non-broadcast (NBMA) also elects a DR and BDR, and it needs neighbors defined by hand.
Note on C
Correct: ip ospf network point-to-point on both ends removes the DR/BDR election and lets the two routers go straight to FULL.
Note on D
Point-to-multipoint also avoids a DR, but it is meant for hub-and-spoke designs and advertises host routes; point-to-point fits exactly two routers.
Best answer: C · why
When there are only two routers connected on a broadcast medium (like Ethernet), configuring the interface as a point-to-point OSPF network type (using ‘ip ospf network point-to-point’) eliminates the unnecessary DR/BDR election process. This can improve convergence time and simplify the OSPF operation, since the DR/BDR election is only beneficial when there are multiple routers on a segment.
- Frame 002 of 018
What command would you use to verify OSPF process information including router ID and area information?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
show ip protocols summarizes all routing processes; the OSPF-specific command for process details is show ip ospf.
Note on B
show ip ospf database lists the LSAs in the link-state database, not a summary of the process.
Note on C
Correct: show ip ospf shows each OSPF process with its router ID, timers, SPF statistics and the areas it belongs to.
Note on D
show ospf process is not an IOS command.
Best answer: C · why
The ‘show ip ospf’ command displays general information about OSPF processes running on the router, including the router ID, area information, SPF statistics, and OSPF timers. This is useful for verifying the overall OSPF configuration and operation.
- Frame 003 of 018
What does the command ‘clear ip ospf process’ do on a Cisco router?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Routes do drop out briefly, but the command restarts the whole OSPF process rather than just flushing the routing table.
Note on B
Correct: it restarts the OSPF process, tears down every adjacency, and the router rebuilds neighbors and reruns SPF.
Note on C
A reset does pick up a newly configured router ID, but it cannot do that without dropping all neighbors.
Note on D
Counters are cleared with ‘clear ip ospf counters’; the process reset is far more disruptive than that.
Best answer: B · why
clear ip ospf process (IOS asks for confirmation) restarts OSPF: all adjacencies go down, the link-state database is rebuilt and SPF runs again. It is the usual way to make a changed router-id take effect. Because every neighbor drops, run it in a maintenance window.
- Frame 004 of 018
What OSPF router type connects an OSPF area to the backbone area (Area 0)?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
A backbone router simply has an interface in area 0; it does not have to touch any other area.
Note on B
Correct: an ABR has interfaces in area 0 and at least one other area and passes summarized routes between them.
Note on C
An internal router has all of its interfaces in one area, so it cannot link that area to the backbone.
Note on D
An ASBR injects routes from outside the OSPF domain, such as redistributed static routes; that is a different role.
Best answer: B · why
An Area Border Router keeps a separate link-state database for each attached area and passes inter-area routes between a regular area and area 0. Internal routers live in one area, backbone routers have an interface in area 0, and an ASBR brings external routes into OSPF.
- Frame 005 of 018
What command would you use to enable OSPFv2 on a router with a process ID of 1 and router ID of 1.1.1.1?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
There is no ‘router ospfv2’ keyword; OSPFv2 is started with ‘router ospf’ followed by the process ID.
Note on B
‘enable ospf’ and ‘set router-id’ are not IOS commands; the set style belongs to other vendors’ CLIs.
Note on C
‘ip ospf’ is an interface-level prefix, and ‘ospf router-id’ is not valid inside the OSPF process.
Note on D
Correct: ‘router ospf 1’ opens the process in global config, and ‘router-id 1.1.1.1’ sets the ID inside it.
Best answer: D · why
router ospf followed by a process ID enters OSPFv2 router configuration; the process ID is locally significant and need not match on neighbors. Inside that mode, router-id 1.1.1.1 sets the router ID by hand, which beats any loopback or interface address. If OSPF is already running, the new ID takes effect after clear ip ospf process.
- Frame 006 of 018
When a router encounters multiple equal-cost OSPF routes to the same destination, how does it manage load balancing between them, and how can an administrator verify this configuration?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Correct: OSPF installs equal-cost paths side by side (four by default, set with maximum-paths), and the route entry shows one next hop per path.
Note on B
Router ID never chooses among equal-cost paths; it identifies the router and breaks DR election ties.
Note on C
The routes already share the lowest metric, so there is nothing to prefer; OSPF keeps all of them.
Note on D
Equal-cost load sharing is on by default, and ‘show ip ospf neighbor’ shows adjacencies, not installed paths.
Best answer: A · why
When OSPF finds several paths to a prefix with the same lowest cost, it installs them all, up to the maximum-paths limit (four by default on IOS), and traffic is shared across them. show ip route, or show ip route ospf, lists each next hop and outgoing interface under the same prefix.
- Frame 007 of 018
Which command will verify that an OSPF route was properly added to the routing table on a router?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
It shows which routing protocols run, their networks and timers, but not whether a route reached the table.
Note on B
This lists interface addresses and up/down status only; no routes appear in it.
Note on C
BGP is a different protocol, and this summary covers BGP peers rather than OSPF routes.
Note on D
Correct: it filters the routing table to entries with an O code, so you see exactly what OSPF installed.
Best answer: D · why
show ip route ospf prints only the routing-table entries learned through OSPF (codes O, O IA, O E1 and O E2), with administrative distance, metric and next hop. show ip protocols shows the routing process settings, and show ip interface brief shows interface status.
- Frame 008 of 018
In OSPF, what is the default hello interval on a point-to-point network?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Thirty seconds is the hello timer on NBMA network types, not on point-to-point links.
Note on B
Correct: point-to-point and broadcast networks use a 10-second hello with a 40-second dead interval.
Note on C
Five seconds is not an OSPF default; you would have to set it with ‘ip ospf hello-interval’.
Note on D
Forty seconds is the default dead interval on this link type, four times the hello timer.
Best answer: B · why
OSPF defaults to a 10-second hello and a 40-second dead interval on point-to-point and broadcast network types. NBMA and point-to-multipoint use 30 and 120 seconds. Both neighbors must agree on these timers or they never become neighbors.
- Frame 009 of 018
Which of the following conditions must be met for two OSPF routers to form an adjacency on a point-to-point network?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Router IDs must be unique, not matching; two routers with the same ID cannot form a proper adjacency.
Note on B
Point-to-point links skip the DR/BDR election entirely, so it cannot be a requirement here.
Note on C
The process ID is local to each router and priority only matters for DR election, so neither has to match.
Note on D
Correct: neighbors must share the area, the hello and dead timers, and the authentication settings to reach FULL.
Best answer: D · why
OSPF neighbors on a point-to-point link must agree on area ID, hello and dead intervals, authentication, subnet and stub flag, and must have unique router IDs. There is no DR or BDR on this network type, and the process ID and priority are locally significant. An MTU mismatch shows up later, as neighbors stuck in EXSTART or EXCHANGE.
- Frame 010 of 018
In OSPF, how is the cost of a route determined when multiple interfaces are involved, and what strategies can be used to influence traffic distribution across these interfaces?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Administrative distance ranks route sources against each other; it plays no part in OSPF’s own path cost.
Note on B
SPF adds every outgoing interface cost along the path; it does not keep just one link’s value.
Note on C
Correct: each hop’s outgoing interface cost is added up, and raising or lowering ‘ip ospf cost’ moves traffic between paths.
Note on D
Costs can be changed at any time with ‘ip ospf cost’ or the reference bandwidth, and SPF reruns to apply them.
Best answer: C · why
OSPF path cost is the sum of the costs of every outgoing interface from the router to the destination. Interface cost defaults to reference bandwidth divided by interface bandwidth. To steer traffic, change ip ospf cost on an interface, change the bandwidth setting, or raise auto-cost reference-bandwidth; equal totals give equal-cost load sharing.
- Frame 011 of 018
Which protocol code in the routing table indicates a route learned through OSPF from another area?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
O E2 marks an external route redistributed into OSPF, with a cost that does not grow inside the domain.
Note on B
O N1 is an NSSA external route, brought in by an ASBR inside a not-so-stubby area.
Note on C
Correct: IA means inter-area, a route an ABR passed into this area from another OSPF area.
Note on D
O E1 is also external, but its cost adds the internal path cost to the advertised metric.
Best answer: C · why
In show ip route, O is an intra-area route, O IA an inter-area route from another area through an ABR, and O E1, O E2, O N1 and O N2 are external routes redistributed into OSPF (N means NSSA). E2, the default for redistribution, keeps the external cost fixed; E1 adds the internal cost.
- Frame 012 of 018
Which command is used to verify a router’s active OSPF neighbors and their states?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
The database view lists the LSAs the router holds, not the neighbors or their adjacency states.
Note on B
This shows OSPF routes installed in the table; a missing neighbor would only be implied.
Note on C
Correct: it lists each neighbor’s router ID, priority, state such as FULL/DR, dead time, address and interface.
Note on D
It shows the routing process, networks and information sources, but not live neighbor states.
Best answer: C · why
show ip ospf neighbor is the first check for adjacency problems: each line gives the neighbor router ID, priority, state (for example FULL/BDR or 2WAY/DROTHER), dead timer, address and local interface. A neighbor stuck in INIT, EXSTART or EXCHANGE points to a parameter or MTU mismatch.
- Frame 013 of 018
In a single-area OSPF network, how is the OSPF cost for an interface calculated, and what potential issues can arise if the reference bandwidth is not appropriately configured?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
OSPF ignores interface delay; delay feeds other protocols’ metrics, not OSPF cost.
Note on B
Correct: cost is reference bandwidth over interface bandwidth, so a 100 Mb/s reference gives Fast, Gigabit and 10-Gigabit links the same cost of 1.
Note on C
Administrative distance only compares route sources; OSPF cost comes from bandwidth and does change with the reference.
Note on D
There is no sum of delays or offsets in OSPF cost; the only inputs are the reference and the interface bandwidth.
Best answer: B · why
OSPF interface cost is reference bandwidth divided by interface bandwidth, with a 100 Mb/s reference by default and a minimum of 1. With that default, FastEthernet, Gigabit and 10-Gigabit links all cost 1, so OSPF cannot prefer the faster path. Raise auto-cost reference-bandwidth (in Mb/s) to the same value on every router in the domain.
- Frame 014 of 018
Which OSPF neighbor state shows that two routers have finished exchanging and synchronizing their link-state databases?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
EXSTART is where the routers agree on master and slave and the first sequence number, before any LSAs move.
Note on B
In LOADING the router is still requesting the LSAs it is missing, so the databases are not yet in sync.
Note on C
Correct: FULL means the link-state databases match and the neighbors are fully adjacent, so SPF can use the routes.
Note on D
2WAY means hellos are seen both ways; DROTHER routers on a LAN stay there with each other and never swap databases.
Best answer: C · why
Neighbors move through DOWN, INIT, 2WAY, EXSTART, EXCHANGE, LOADING and FULL. Database descriptions are exchanged in EXCHANGE and missing LSAs are requested in LOADING; FULL means the databases match. On a broadcast segment, two DROTHER routers stop at 2WAY with each other, which is normal.
- Frame 015 of 018
On a point-to-point OSPF network, how does the absence of a DR/BDR election affect neighbor relationships and overall IP connectivity?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Correct: with only two routers on the link there is nothing to elect, so they become fully adjacent and exchange LSAs directly.
Note on B
Stopping at 2WAY happens between DROTHERs on a LAN; point-to-point neighbors always continue to FULL.
Note on C
No election runs at all on this network type; ‘show ip ospf neighbor’ shows the state as FULL/-.
Note on D
OSPF forms the adjacency normally; no static route is involved in building OSPF neighbor relationships.
Best answer: A · why
On the point-to-point network type there is no DR or BDR election. The two neighbors move straight from 2WAY to database exchange and reach FULL, shown as FULL/- in show ip ospf neighbor. This is why serial links, and Ethernet links set with ip ospf network point-to-point, converge a little faster than broadcast links.
- Frame 016 of 018
What is the purpose of the OSPF hello packet?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Routing information travels in LSAs inside update packets, not in hellos.
Note on B
Database sync uses DBD, LSR and LSU packets after the neighbors are already known.
Note on C
Correct: hellos find neighbors on each link and keep the relationship alive until the dead timer expires.
Note on D
Hellos carry the priority and DR/BDR fields used in the election, but electing the DR is not their only job.
Best answer: C · why
OSPF hello packets go to 224.0.0.5 and discover neighbors, check that parameters match (area, timers, subnet, authentication, stub flag) and keep each adjacency alive. If no hello arrives within the dead interval, the neighbor is declared down. Hellos also carry the priority and DR/BDR fields that the election uses.
- Frame 017 of 018
What is the main purpose of First Hop Redundancy Protocols (FHRPs) in a network?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Redundant paths between subnets come from the routing protocol; FHRPs protect the hosts’ gateway address.
Note on B
Balancing several internet links is a routing or SD-WAN task; an FHRP works on one LAN subnet.
Note on C
Keeping routing tables in step is what OSPF and other routing protocols do; FHRPs do not exchange routes.
Note on D
Correct: routers share a virtual IP and MAC that hosts use as the default gateway, and another router takes over if the active one fails.
Best answer: D · why
Hosts usually have one static default gateway. HSRP, VRRP and GLBP let two or more routers share a virtual IP address and virtual MAC address on the subnet, so if the active router fails, a standby router takes over the same gateway address and hosts need no change.
- Frame 018 of 018
Which command is used to advertise a network in OSPF?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
The network command takes a wildcard mask, not slash notation, so IOS rejects ‘/24’ here.
Note on B
There is no ‘advertise’ command in OSPF router configuration mode.
Note on C
Correct: inside ‘router ospf’, the address plus wildcard 0.0.0.255 enables OSPF on matching interfaces in area 0.
Note on D
Interface mode uses ‘ip ospf 1 area 0’; ‘ip ospf network’ sets the network type, not a prefix.
Best answer: C · why
In router ospf mode, network 192.168.1.0 0.0.0.255 area 0 enables OSPF on any interface whose address falls in 192.168.1.0/24 and puts it in area 0, so that connected subnet is advertised. The mask is a wildcard, not a subnet mask. The interface-level alternative is ip ospf 1 area 0.
OSPF and FHRP questions
Is multi-area OSPF part of the CCNA?
Not as a configuration topic: both the v1.1 and v2.0 topic lists specify single area. Recognizing the router roles and route codes of a multi-area design is still useful context, because OSPF output and documentation use them.
Should I still study GLBP?
Yes for v1.1: topic 3.5 covers FHRPs in general and GLBP is the one that load-shares, so know how it differs. The v2.0 list names only HSRP and VRRP.
How deep does the HSRP and VRRP material go?
v1.1 asks for purpose and concepts only. v2.0 asks you to interpret HSRP and VRRP status, which in practice means reading show standby and show vrrp output, so configuring a group in a lab is the quickest way to learn what that output looks like.
Concepts in this study area
- OSPF DR/BDR electionPriority, router ID, priority 0 and non-preemption on broadcast links.
- HSRP vs VRRP vs GLBPStandards, role names, preemption defaults and load sharing.