Lists I've Memorized Flashcards
What are the 13 BGP Path Attributes?
- Highest weight
- Highest Local pref
- Local origin over external origin
- AIGP
- Shortest AS path
- Lowest origin type
- Lowest MED
- eBGP over iBGP
- Lowest IGP next hop cost
- If eBGP then oldest route
- Lowest peer router ID
- Shortest Cluster List
- Lowest neighbor IP address
What are the 5 different IGMP messages along with their types numbers?
- Ver 2 Membership Report - 0x16
- Ver 1 Membership Report - 0x12
- Ver 2 Leave Group - 0x17
- General Membership Query - 0x11
- Group Specific Query - 0x11
What are the 4 fields in an IGMP message?
- Type
- Max Response Time
- Checksum
- Group Address
What 4 fields did IEEE 802.1q add to the VLAN packet structure?
- Tag Protocol Identifier (TID)
- Priority Code Point (PCP)
- Drop Eligible Indicator (DEI)
- VLAN Identifier (VLAN ID)
What are the 3 types of packets that need to be process switched?
- Packets sourced by or destined for the router itself
- Packets too complex for hardware (packets with IP options)
- Packets that need extra information that isn’t already known (like ARP)
What 5 things happen when a packet is punted by CEF to be process switched?
- ip_input process checks the routing table and ARP for next hop routers IP address, outgoing interface and MAC
- Overwrites source MAC with its own MAC, and destination MAC with next hop router’s MAC
- Decrements TTL
- Recomputes checksum of IP header
- Delivers packet to next hop router
In CEF switching what 7 things happen in CEF once a packet is received?
- FIB checked for valid entry - glean if none
- Adjacency table checked for destination MAC and IP - invoke ARP if none
- Destination MAC overwritten with info from Adjacency Table
- Source MAC overwritten with MAC from egress interface
- TTL is decremented
- Header checksum is re-computed
- Packet delivered to next hop router
What are the 7 fields in a Configuration BPDU?
- STP Type
- Root Path Cost
- Root Bridge Identifier
- Local Bridge Identifier
- Hello Timer
- Forward Delay Timer
- Max Age
How does a switch initially identify its Root Port (RP) along with 4 tie-breakers?
- Port with lowest path cost to the Root
- Port who’s neighbor has the lowest System Priority
- Port whose neighbor has the lowest base MAC address
- Port whose neighbor has the lowest port priority
- Port whose neighbor has the lowest interface index number
What are the 3 port states in RSTP?
- Discarding
- Learning
- Forwarding
What are the 4 RSTP Port Roles?
- Root Port (RP)
- Designated Port (DP)
- Alternate Port
- Backup Port
What are the short mode port costs for 10 Mbps, 100 Mbps, 1 Gbps, 10 Gbps, 20 Gbps, 100 Gbps, 1 Tbps, 10 Tbps?
- 10 Mbps - 100
- 100 Mbps - 19
- 1 Gbps - 4
- 10 Gbps - 2
- 20 Gbps and higher - 1
What are the long mode port costs for 10 Mbps, 100 Mbps, 1 Gbps, 10 Gbps, 20 Gbps, 100 Gbps, 1 Tbps, 10 Tbps?
- 10 Mbps - 2,000,000
- 100 Mbps - 200,000
- 1 Gbps - 20,000
- 10 Gbps - 2,000
- 20 Gbps - 1,000 (half of 10 Gbps)
- 100 Gbps - 200
- 1 Tbps - 20
- 10 Tbps - 2
What are 4 causes of Layer 2 forwarding loops?
- STP disabled
- misconfigured Load Balancer
- misconfigured Virtual Switch that bridges 2 physical ports
- End users using a dumb switch or hub
What 9 parameters must match in order for interfaces to be members of the same port channel?
- Load Interval
- Storm Control
- MTU
- Speed
- Duplex
- Access/Trunk
- Native VLAN
- Allowed VLANs
- L2 / L3
What are 5 enhancements introduced by DUAL?
- Rapid Convergence
- Sends updates only when there’s a change
- Uses Hellos and forms Neighborships
- Uses bandwidth, delay, reliability, load and MTU
- can Load Balance across equal or un-equal cost links
What are the 5 packet types used by EIGRP when communicating with other routers?
- Hello
- Query
- Request
- Update
- Reply
What are the 5 types of packets used by OSPF?
- Hello
- DD
- Link State Request (LSR)
- Link State Update (LSU)
- Link State Ack
What are 9 fields in an OSPF Hello packet?
- Router ID
- Authentication options
- Area ID
- Interface mask
- Interface priority
- Hello Interval
- Dead Interval
- DR and BDR IP addresses
- Active neighbors
What are the 8 OSPF neighbor states?
- Down
- Attempt
- Init
- 2-way
- ExStart
- Exchange
- Loading
- Full
What are the 10 requirements for OSPF routers to become neighbors?
- Unique router IDs
- Authentication matches
- Area ID matches
- Area flags match
- Interfaces on a common subnet
- MTUs match
- Hello timer matches
- Dead timer matches
- DR enablement matches
- Network type matches
What are 3 OSPF interface costs?
- T1 = 64
- 10 Mbps Ethernet = 10
- 100 Mbps Ethernet and faster = 1
What are the 5 OSPF media types?
- Broadcast
- Non-broadcast
- Point-to-point
- Point-to-multipoint
- Loopback