Windows Server 2008 R2's DNS Manager GUI indeed doesn't provide a direct interface for setting Time-To-Live (TTL) values on individual DNS records. While you can configure the default TTL for an entire zone through the SOA (Start of Authority) record, per-record TTL customization requires alternative methods.

The most efficient way to set per-record TTL is using PowerShell. Here's a complete example of how to modify TTL for an A record:

# Import DNS module if not already loaded
Import-Module DnsServer

# Set TTL for specific record
$ZoneName = "example.com"
$RecordName = "webserver"
$NewTTL = "01:00:00" # 1 hour in .NET TimeSpan format

# For A record
Set-DnsServerResourceRecord -ZoneName $ZoneName -Name $RecordName -RRType "A" -TTL $NewTTL

# For CNAME record
Set-DnsServerResourceRecord -ZoneName $ZoneName -Name "www" -RRType "CNAME" -TTL $NewTTL

For environments where PowerShell isn't available, you can use the dnscmd utility:

dnscmd /RecordAdd example.com webserver A 192.168.1.100 /ttl 3600

When working with per-record TTL values:

• Lower TTLs increase DNS traffic but allow faster propagation of changes
• Higher TTLs reduce server load but delay updates across the internet
• Common TTL values: 300 (5 min), 3600 (1 hr), 86400 (24 hrs)

After modifying TTL values, verify using either method:

# PowerShell verification
Get-DnsServerResourceRecord -ZoneName "example.com" -Name "webserver" -RRType "A"

# Command line verification
nslookup -debug -type=a webserver.example.com

For wildcard records (*), the syntax differs slightly in PowerShell:

Set-DnsServerResourceRecord -ZoneName "example.com" -Name "@" -RRType "A" -TTL "00:30:00" -RecordData "192.168.1.100"

Windows Server 2008 R2's DNS Manager lacks a GUI option for setting Time-To-Live (TTL) values on individual resource records. While you can configure zone-level TTL through the Start of Authority (SOA) record properties, this applies uniformly to all records in the zone.

The DNSCmd utility and PowerShell provide programmatic control over per-record TTL settings. Here's how to modify a record's TTL:

# PowerShell example to set A record TTL
Import-Module DnsServer
Add-DnsServerResourceRecordA -Name "webserver" 
    -ZoneName "contoso.com" 
    -IPv4Address "192.168.1.100" 
    -TTL (New-TimeSpan -Minutes 30)

The legacy command-line tool can achieve similar results:

dnscmd /recordadd contoso.com webserver A 192.168.1.100 /ttl 1800

When setting custom TTL values:

• Shorter TTL (300-900 seconds) allows faster DNS changes propagation
• Longer TTL (86400+ seconds) reduces DNS query load
• Critical infrastructure records typically need 3600+ seconds

For bulk operations, consider this PowerShell script pattern:

$records = Import-Csv .\dns_updates.csv
foreach ($r in $records) {
    Set-DnsServerResourceRecord -ZoneName $r.Zone 
        -Name $r.Hostname 
        -RRType $r.Type 
        -NewTTL (New-TimeSpan -Minutes $r.TTLMinutes)
}

Remember that modifying TTL values affects:

• DNS caching behavior
• Record update propagation time
• DNS server performance during changes