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Computer Networks → Introduction to Computer Networks 33

BGP confederation uses
Sub-ASes within one AS to reduce iBGP mesh
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BGP RR cluster avoids need for
Full iBGP mesh within a cluster
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RPKI ROA stands for
Route Origin Authorization
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BGPSEC provides
BGP path validation using cryptographic signatures
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RTBH stands for
Remotely Triggered Black Hole
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DNS SOA record defines
Zone authority and timing parameters
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DNS NS record specifies
Authoritative name server for zone
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DNS SRV record is used for
Service location (used by SIP XMPP etc)
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DNS DNSSEC uses which records for signing
RRSIG DNSKEY DS and NSEC
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DNS split horizon serves
Different answers based on source of query
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Anycast DNS routes to
Nearest DNS server by routing metric
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EDNS0 extends DNS to support
Larger UDP packets beyond 512 bytes
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DNS QNAME minimization
Reduces privacy leakage by sending minimal query names
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Email DKIM signs
Email content with private key for verification
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Email SPF record lists
Authorized sending IP addresses for domain
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DMARC policy can instruct receivers to
Quarantine or reject emails failing SPF/DKIM checks
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Greylisting temporarily rejects unknown senders to
Force retry (legitimate servers retry spam bots often dont)
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Email MIME allows
Sending non-text content like images and attachments
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Base64 in email is used to
Encode binary data as text for transmission
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PGP email encryption uses
Combination of symmetric and asymmetric cryptography
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S/MIME uses
X.509 certificates for email signing and encryption
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SDN northbound interface connects
Applications to SDN controller
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SDN southbound interface connects
SDN controller to network devices
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SDN eastbound westbound interfaces connect
Multiple SDN controllers for federation
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OpenFlow table-miss action can
Send packet to controller
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SDN proactive flow setup
Pre-installs forwarding rules before traffic arrives
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SDN reactive flow setup
Installs flow on first packet sent to controller
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OF-Config manages
OpenFlow switch configuration (separate from OpenFlow)
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Faucet is
Open source SDN controller using OpenFlow
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P4Runtime is
API for controlling P4-programmed data planes
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Intent NBI in SDN expresses
High-level network intent abstracting device details
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VTP domain name mismatch
Prevents VLAN propagation between switches
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VTP transparent mode
Passes VTP messages but does not participate
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Computer Networks → Application Layer 2

DHCP option 43 is for
Vendor-specific information
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DHCP option 82 is for
Relay agent information (subscriber ID)
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Computer Networks → FTP and SMTP 2

SMTP EHLO command
Identifies client and requests extended features
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SMTP STARTTLS upgrades connection from
Plain to TLS encrypted
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Computer Networks → Switching Techniques 3

VLAN ID range for standard VLANs is
1-4094
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VLAN 1 on Cisco is
Default native VLAN
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Native VLAN on trunk sends frames
Without 802.1Q tag
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