One table, every field
Trimmed show ip route from a branch router (documentation and lab addresses)
R1#show ip routeCodes: L - local, C - connected, S - static, O - OSPF, * - candidate default (other codes trimmed)Gateway of last resort is 203.0.113.1 to network 0.0.0.0S* 0.0.0.0/0 [1/0] via 203.0.113.1 10.0.0.0/8 is variably subnetted, 4 subnets, 4 masksC 10.1.12.0/30 is directly connected, GigabitEthernet0/1L 10.1.12.1/32 is directly connected, GigabitEthernet0/1O 10.4.0.0/16 [110/3] via 10.1.12.2, 00:41:07, GigabitEthernet0/1S 10.4.9.0/24 [1/0] via 203.0.113.1 203.0.113.0/24 is variably subnetted, 2 subnets, 2 masksC 203.0.113.0/30 is directly connected, GigabitEthernet0/0L 203.0.113.2/32 is directly connected, GigabitEthernet0/0L entries are /32 routes for the router’s own interface addresses; C entries are the subnets those interfaces sit on. The bracketed pair is decoded on administrative distance vs metric.
Predict the next hop from that table
A packet for 10.4.9.20
Two entries cover it, 10.4.0.0/16 from OSPF and 10.4.9.0/24 static. The /24 is longer, so it wins before distance or metric are compared, and the packet leaves toward 203.0.113.1. The rule has its own page: longest prefix match.
A packet for 10.4.200.1
Only the /16 covers it, since the /24 ends at 10.4.9.255, so it follows OSPF to 10.1.12.2.
A packet for 198.51.100.7
Nothing matches except 0.0.0.0/0, so the gateway of last resort, 203.0.113.1, takes it.
A packet for 10.1.12.2
The connected /30 covers it. The router ARPs for 10.1.12.2 and delivers it on Gi0/1 directly.
Static route forms
| Form | Points at | What to watch |
|---|---|---|
| Next hop | A neighbor’s address | The router has to resolve 10.1.12.2 through another route, a recursive lookup. |
| Exit interface | A local interface | Listed as directly connected. On Ethernet the router ARPs for every destination and relies on proxy ARP at the neighbor. |
| Fully specified | A local interface, then the neighbor’s address | Interface and next hop together: no recursion, and the ARP target is the next hop. |
| Default | Destination 0.0.0.0, mask 0.0.0.0 | Shows as S* and becomes the gateway of last resort. |
| Floating | Any form above, plus a distance value at the end | Compare that distance with the route this one backs up. |
| IPv6 | A prefix/length, then a next hop or interface | Needs ipv6 unicast-routing. A link-local next hop must be paired with the exit interface. |
Where the entries come from
Three sources fill the table. Connected and local routes appear as soon as an interface with an address comes up/up; static routes are typed in; dynamic routes arrive from a routing protocol. On the CCNA that protocol is Open Shortest Path First (OSPF), a link-state interior gateway protocol, covered next in single-area OSPF and first-hop redundancy.
Distance-vector routing comes up as the contrast: a distance-vector router knows what its neighbors tell it, while a link-state router builds a map of its area and runs the shortest-path calculation itself.
When one protocol finds several paths to a prefix with the same metric, the router installs them side by side and shares traffic across them; that is equal-cost load sharing, and it shows as two via lines under one prefix.
Cisco’s v1.1 list gives this area three of the five IP Connectivity items: the parts of a routing table (3.1), how the router makes its forwarding decision (3.2), and IPv4 and IPv6 static routes, including default, network, host and floating forms (3.3).
In v2.0 the same ground narrows to two topics, reading the table for the next hop and troubleshooting IPv4 and IPv6 static routes (3.1 and 3.2); the v2.0 changeover page has the timing.
The IPv6 table
show ipv6 route reads the same way with longer prefixes: C marks connected networks, L the router’s own addresses as /128 entries, and S and O static and OSPF routes. Next hops learned from a neighbor are usually its link-local address, so the exit interface is printed beside it. The IPv6 prefix rules themselves are on IPv6 addressing.
Frames: Routing & static routes
Route codes, static syntax, floating routes and the order a router decides in. For another pass in a different order, open the practice test filtered to routing.
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 020 · 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 020
Which command configures a floating static default route (a backup default route) that uses next-hop 192.168.1.1 and an administrative distance of 100?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
The next hop is wrong: this points to 192.168.1.2 instead of 192.168.1.1.
Note on B
With no distance given, the route takes the static default of 1, so it would win over other routes instead of floating behind them.
Note on C
0.0.0.255 is not the mask of a default route; the default route is written 0.0.0.0 0.0.0.0.
Note on D
Correct: ip route 0.0.0.0 0.0.0.0 192.168.1.1 100 sets the default route with AD 100, so it stays out of the table while a lower-AD default exists.
Best answer: D · why
A default route is written ip route 0.0.0.0 0.0.0.0 followed by the next hop. A number added at the end sets the administrative distance; 100 instead of the static default of 1 makes this a floating route, kept out of the routing table while a default route with a lower AD is present and installed when that route disappears. 0.0.0.255 is not a valid mask here, and the next hop must be 192.168.1.1.
- Frame 002 of 020
In a scenario where a router uses recursive lookup for static routes, under what condition can recursion lead to a routing loop?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Correct: if each static route’s next hop is reachable only through the other, the lookup never resolves to a connected exit, so traffic or the lookup loops.
Note on B
Recursive lookup is how any route’s next hop gets resolved; OSPF external routes are not a special case.
Note on C
Recursion can take several lookups, one per level, until a connected route is found; nothing limits it to one.
Note on D
A router resolves recursively for any route whose next hop is not directly connected, whether or not dynamic routes exist.
Best answer: A · why
A recursive lookup can lead to a routing loop if the next-hop of a static route refers to another recursive static route that eventually points back to the original route without a directly connected exit interface.
- Frame 003 of 020
In a routing table entry showing ‘S [1/0] via 192.168.1.1’, what does the letter ‘S’ represent?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Correct: S marks a static route, and [1/0] shows the default static AD of 1 and a metric of 0.
Note on B
Subnet routes are not shown with an S code; connected subnets use C and local interface addresses use L.
Note on C
There is no ‘system route’ code in the IOS routing table.
Note on D
IOS has no ‘source route’ code; S stands for static.
Best answer: A · why
In show ip route output, S marks a static route configured by hand with ip route. The bracket [1/0] gives the administrative distance (1 for a static route) and the metric (0). Other common codes are C for connected networks, L for local interface addresses and O for OSPF, and S* marks a static default route that serves as the gateway of last resort.
- Frame 004 of 020
Which command would create a static IPv4 route to the 172.16.0.0/16 network with an administrative distance of 150 through the next-hop address 10.1.1.1?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Classic IOS ip route takes a dotted mask, not a /16 prefix length, so this form is rejected.
Note on B
This builds the route but leaves the AD at the static default of 1, not 150.
Note on C
ip static-route is not an IOS command, and the distance is not written with an ad keyword.
Note on D
Correct: ip route 172.16.0.0 255.255.0.0 10.1.1.1 150 gives the network, mask and next hop, with the AD of 150 as the last number.
Best answer: D · why
The IOS syntax is ip route followed by the network, the dotted-decimal mask, the next hop or exit interface, and an optional administrative distance. ip route 172.16.0.0 255.255.0.0 10.1.1.1 150 therefore installs the route with AD 150, which makes it a floating route that stays behind an OSPF route (AD 110) to the same network.
- Frame 005 of 020
What command would configure a fully specified static route to network 192.168.20.0/24 via next-hop 10.1.1.1 and exit interface GigabitEthernet0/0?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
The interface comes after the next hop here; IOS expects the exit interface first and then the next-hop address for a fully specified route.
Note on B
Classic IOS ip route needs a dotted mask, not /24, so this form is rejected.
Note on C
This is a valid next-hop route, but it leaves out the exit interface, so it is not fully specified.
Note on D
Correct: a fully specified route lists the exit interface and then the next hop: ip route 192.168.20.0 255.255.255.0 GigabitEthernet0/0 10.1.1.1.
Best answer: D · why
The command ‘ip route 192.168.20.0 255.255.255.0 GigabitEthernet0/0 10.1.1.1’ configures a fully specified static route. This type of static route includes both the exit interface (GigabitEthernet0/0) and the next-hop IP address (10.1.1.1). Fully specified static routes are useful in multiaccess networks where the exit interface alone isn’t sufficient to determine the next hop.
- Frame 006 of 020
When examining a routing table entry ‘O 192.168.10.0/24 [110/20] via 10.0.0.2, 00:15:08, GigabitEthernet0/0’, what information does the value ‘20’ represent?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
The administrative distance is the first number in the brackets, 110, the default for OSPF.
Note on B
OSPF does not count hops; the 20 here is a cost based on interface bandwidth.
Note on C
The area is not shown in this line at all; the brackets hold the AD and the metric.
Note on D
Correct: in [110/20], 110 is OSPF’s AD and 20 is the total OSPF cost to reach 192.168.10.0/24.
Best answer: D · why
In the routing table entry ‘O 192.168.10.0/24 [110/20]’, the value ‘20’ represents the metric or cost of the route. For OSPF routes (indicated by ‘O’), this value is the cumulative cost to reach the destination network, calculated based on interface bandwidths along the path. Lower metrics are preferred.
- Frame 007 of 020
Which command would configure an IPv6 static route to network 2001:DB8:ACAD::/64 via next-hop 2001:DB8:1:1::1?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
ipv6 static-route is not an IOS command; static IPv6 routes use ipv6 route.
Note on B
Correct: ipv6 route 2001:DB8:ACAD::/64 2001:DB8:1:1::1 names the prefix with its length and then the next hop.
Note on C
ip route is the IPv4 command; it does not accept an IPv6 prefix.
Note on D
IOS does not use a via keyword; the next hop follows the prefix directly.
Best answer: B · why
The command ‘ipv6 route 2001:DB8:ACAD::/64 2001:DB8:1:1::1’ configures an IPv6 static route specifying the destination network prefix (2001:DB8:ACAD::/64) and the next-hop IPv6 address (2001:DB8:1:1::1).
- Frame 008 of 020
A network administrator configures a floating static route with an administrative distance of 80 to reach the network 192.168.10.0/24 via the next-hop IP address 10.1.1.1. Which line shows how this route will be displayed in the output of the ‘show ip route’ command?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Correct: the brackets show [AD/metric], so a static route with AD 80 appears as [80/0] via the next hop 10.1.1.1.
Note on B
directly connected appears for static routes that name only an exit interface; a route through a next-hop address is shown with via.
Note on C
[1/0] is a static route with the default AD of 1; this one was configured with 80.
Note on D
This drops the AD and metric and misuses directly connected; a next-hop static route is shown with via and its [AD/metric].
Best answer: A · why
show ip route prints a static route as S, the prefix, [administrative distance/metric] and the next hop after via. A route configured with AD 80 therefore appears as S 192.168.10.0/24 [80/0] via 10.1.1.1. directly connected appears only for static routes that name an exit interface, and [1/0] would mean the default static AD. A floating route shows up in the table only while it is installed.
- Frame 009 of 020
In a scenario where an IPv4 static route and an OSPF route exist for the same destination prefix, how does the router’s control plane prioritize these routes?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Metrics are compared only between routes from the same source; a static route and an OSPF route have metrics on different scales.
Note on B
Routes from different sources are not load balanced by default; only the one with the lowest AD is installed.
Note on C
OSPF’s AD of 110 is higher than a static route’s 1, so OSPF loses unless the static route is made floating.
Note on D
Correct: for the same prefix the route with the lowest AD is installed, and a static route (AD 1) beats OSPF (AD 110) unless its AD is raised.
Best answer: D · why
For two routes to the same prefix, the router installs the one with the lower administrative distance. A static route has AD 1 by default and OSPF has 110, so the static route is preferred unless it is configured as a floating route with a higher AD. Metrics only compare routes from the same protocol, and a more specific prefix would win before AD is considered.
- Frame 010 of 020
A Cisco router has two routes to the network 172.16.0.0/16: one received via OSPF (AD 110) and a floating static route configured with AD 150. Which route is installed in the routing table and why?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Routes from different sources are not load balanced; only the lowest-AD route goes into the table.
Note on B
A static route wins only with its default AD of 1; at AD 150 it floats behind OSPF’s 110.
Note on C
Both routes have the same /16 prefix, so longest match cannot separate them; AD decides.
Note on D
Correct: with equal prefixes the lower AD wins, so the OSPF route (110) is installed and the static route (150) waits as a backup.
Best answer: D · why
The router installs the route with the lower administrative distance. OSPF’s AD (110) is lower than the floating static route’s AD (150), making the OSPF route the preferred one.
- Frame 011 of 020
What is the purpose of a floating static route in a redundant network design, and how does its administrative distance mitigate potential routing conflicts?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
A floating static route is not used alongside the primary; its higher AD keeps it out of the table while the primary exists.
Note on B
Correct: a floating static route is a backup set with an AD above the primary route’s, so it is installed only when the primary disappears.
Note on C
It does the reverse: a floating route deliberately loses to dynamic routes until they are gone.
Note on D
Its AD is raised, not lowered, and AD does not reduce any routing table cost.
Best answer: B · why
A floating static route is configured with a higher administrative distance so that it acts as a backup route, only being used when preferred dynamic routes become unavailable. The higher AD prevents it from conflicting with lower-AD routes during normal operation.
- Frame 012 of 020
Which value does a router use to choose between routes to the same destination learned from different routing protocols?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Each protocol’s metric has its own scale, such as OSPF cost, so metrics cannot be compared across protocols.
Note on B
Correct: administrative distance ranks route sources, so for the same prefix the route from the lowest-AD source is installed.
Note on C
Hop count is the metric of some distance-vector protocols; OSPF uses cost, so hop count cannot compare protocols.
Note on D
Bandwidth feeds into some metrics, such as OSPF cost, but it is not used to compare one protocol with another.
Best answer: B · why
Each routing protocol uses its own metric, such as OSPF cost or a hop count, so metrics cannot be compared between protocols. When two sources offer the same prefix, the router uses administrative distance, a trust ranking of the source: connected 0, static 1, OSPF 110, and so on. The lowest AD wins, and the metric only breaks ties within one protocol.
- Frame 013 of 020
Which command on a Cisco router will display the routing table?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
ping tests reachability with ICMP echo; it shows nothing about the routing table.
Note on B
show ip interface shows per-interface IP settings, such as applied ACLs and helper addresses, not the routes.
Note on C
Correct: show ip route displays the IPv4 routing table with route codes, [AD/metric], next hops and exit interfaces.
Note on D
show running-config shows configured commands, including static routes, but not learned routes or the table the router actually uses.
Best answer: C · why
show ip route displays the IPv4 routing table: connected, local, static and learned routes with their codes, [AD/metric], next hops and exit interfaces. show ip interface shows interface-level IP settings, show running-config shows the configuration only, and ping tests reachability.
- Frame 014 of 020
When a router has two routes to the same destination with identical administrative distances and prefix lengths, but differing metrics, how does it determine which route to install?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Route choice is deterministic; with equal AD and prefix the metric decides, and nothing is random.
Note on B
The prefixes are equal by definition here, so longest match cannot decide.
Note on C
Correct: same prefix and same AD means the same source, so the lower metric (a lower OSPF cost, for example) wins; equal metrics would be load balanced.
Note on D
A higher metric means a worse path; routers prefer the lower one.
Best answer: C · why
If administrative distance and prefix length are identical, the router selects the route with the lower metric value.
- Frame 015 of 020
Which statement is true about the relationship between routing protocols and the gateway of last resort?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Correct: a default route from any source, such as a static 0.0.0.0/0 or a default advertised by OSPF, can become the gateway of last resort.
Note on B
OSPF can advertise a default route, for example with default-information originate, and that route can become the gateway of last resort.
Note on C
Static default routes are common, but dynamic protocols can supply the default route too.
Note on D
An exterior gateway protocol can supply a default, but so can OSPF or a static route; nothing requires one.
Best answer: A · why
The gateway of last resort is the next hop of the router’s default route, 0.0.0.0/0, used when no more specific route matches. That default can be configured as a static route or learned from a routing protocol such as OSPF, which can advertise one with default-information originate. If several sources offer a default, the one with the lowest administrative distance is installed.
- Frame 016 of 020
Which command is used to configure a directly attached static route to network 172.16.0.0/16 through interface GigabitEthernet0/1?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Correct: ip route 172.16.0.0 255.255.0.0 GigabitEthernet0/1 names only the exit interface, which makes it a directly attached static route.
Note on B
ip static-route is not an IOS command.
Note on C
There is no direct keyword; naming the interface after the mask is what makes the route directly attached.
Note on D
Classic IOS ip route needs a dotted-decimal mask, so the /16 form is rejected.
Best answer: A · why
The command ‘ip route 172.16.0.0 255.255.0.0 GigabitEthernet0/1’ configures a directly attached static route, specifying the network (172.16.0.0), subnet mask (255.255.0.0), and exit interface (GigabitEthernet0/1).
- Frame 017 of 020
Which table does a router use to determine the next hop for a packet in a network?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
The ARP table maps IP addresses to MAC addresses once the next hop is known; it does not choose the next hop.
Note on B
Correct: the routing table matches the destination to the best route and gives the next hop and exit interface.
Note on C
The MAC address table is what switches use to forward frames by MAC; it holds no IP next hops.
Note on D
The CAM table is the switch hardware that stores the MAC table, so it does not pick IP next hops either.
Best answer: B · why
A router uses its routing table to determine the next hop and the outbound interface for forwarding a packet through the network. The CAM table and the MAC address table are used by switches to link MAC addresses to ports. The ARP table is used to map IP addresses to MAC addresses.
- Frame 018 of 020
Which criterion is used first when a router makes forwarding decisions for an IP packet?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Administrative distance only matters between routes with the same prefix, after the longest match is found.
Note on B
The metric breaks ties within one protocol, after both prefix length and AD.
Note on C
Correct: the router first takes the most specific matching prefix; AD and metric only choose among routes with that same prefix.
Note on D
The router ID identifies a router inside OSPF; it plays no part in forwarding a packet.
Best answer: C · why
When making forwarding decisions, a router first looks for the longest prefix match in the routing table. This means it selects the route with the most specific subnet mask (highest prefix length) that matches the destination IP address, regardless of administrative distance or metric.
- Frame 019 of 020
How does a router determine which path to use when it has both a static route and an OSPF route to the same destination network?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Metrics from a static route and from OSPF cannot be compared; the router uses AD first.
Note on B
Correct: the router installs the route with the lower AD, so by default the static route (1) beats OSPF (110).
Note on C
OSPF is not preferred by default; its AD of 110 loses to a static route’s 1.
Note on D
Routes from different sources are not load balanced; only the lowest-AD route is installed.
Best answer: B · why
When a router has both a static route and an OSPF route to the same destination network, it selects the path with the lowest administrative distance. By default, static routes have an administrative distance of 1, while OSPF routes have an administrative distance of 110. Therefore, the static route would be preferred unless it was configured as a floating static route with a higher administrative distance.
- Frame 020 of 020
A network engineer needs to set a static route to a host within a specific network. Which prefix length should be used for this route?
Pick an option. The verdict shows here; open the note under any option to see why.
Note on A
Correct. A /32 mask (255.255.255.255) matches all 32 bits, so the route covers exactly one IPv4 address.
Note on B
A /0 prefix matches every address. It is the prefix of a default route, not a route to one host.
Note on C
A /24 covers 256 addresses, a whole subnet. It would send traffic for every host in that range the same way.
Note on D
A /16 covers 65,536 addresses. It is far broader than a single host.
Best answer: A · why
The prefix length says how many leading bits of the destination must match. A host route matches all 32 bits of an IPv4 address, so it uses /32 (mask 255.255.255.255), for example ‘ip route 192.0.2.10 255.255.255.255 10.1.1.1’. Because it is the longest possible prefix, a host route wins over any subnet or default route that also covers that address. The IPv6 equivalent is /128.
Routing table questions
What is the difference between a routed protocol and a routing protocol?
A routed protocol is what gets forwarded: IPv4 and IPv6 packets. A routing protocol is how routers exchange the entries that forward them, OSPF on this exam. The routing table is where the two meet.
How much of the blueprint is this area?
Cisco weights IP Connectivity at 25% in the v1.1 exam topics, and this page holds three of its five topics. Splitting the domain weight equally across its items puts this area at about 15% by our estimate; Cisco does not publish per-item weights. In v2.0, IP Routing is 20%, and the two topics here come to about 10% by the same method (v2.0 exam topics, as of October 29, 2026).
Why does a ping fail when the route clearly exists?
Ping needs a path in both directions. The far router also needs a route that covers the source address of the echo request; a static route on the near side alone delivers the request and leaves the reply with nowhere to go. An extended ping from a chosen source interface tests exactly that.
Concepts in this study area
- AD vs metricDefault AD values and the [AD/metric] pair in a routing-table entry.
- Longest prefix matchMost specific prefix first, then AD, then metric.