When Nobody Else Will Step Up, You Have To

When you genuinely care about your customer and see no one else stepping up to fix the mess, you just have to dive in and get it done yourself.

Last week, I found myself in exactly that situation. What started as a "quick look" at some application issues turned into 8+ hours of intense troubleshooting across multiple days. And it all came down to something most people take for granted: DNS.

The Million-Dollar Question: Is DNS as Important as the Network?

I think so. And after last week, I KNOW so.

Here's the thing: Everyone talks about network outages. They're dramatic, visible, and everyone understands "the network is down." But DNS issues? They're the silent killers. Insidious. Hard to diagnose. And absolutely devastating when they go wrong.

In our case, DNS wasn't just causing problems—it was causing multiple outages for my customer. Applications were crashing left and right, all because of DNS timeouts and potential packet loss. Every minute of downtime was bleeding money.

The Perfect Storm: When Too Many Cooks Spoil the Network

Picture this: Four different support teams, all working on the same problem:

• The DNS server team
• The DNS provider team
• The firewall team
• The network team

Sounds like overkill, right? You'd think with that much brainpower, the problem would be solved in minutes.

Wrong.

Each team was working in their own silo. The DNS folks blamed the network. The network team pointed at the firewall. The firewall team said it was a server issue. And round and round we went.

Nobody was looking at the big picture. Nobody was correlating data across domains. It was like having four doctors examining different parts of an elephant and nobody realizing it's an elephant.

Taking the Reins: When Experience Meets Urgency

That's when I decided to jump in.

With my troubleshooting experience from years at Cisco TAC, I could see what was happening. This wasn't a time for politics or "not my job" attitudes. Every minute of downtime meant real money lost, real users affected, real business impact.

I wasn't about to let that slide. 😪

The Needle in the Haystack: Analyzing Millions of DNS Packets

Now, here's where it gets technical. And slightly insane.

Dealing with DNS traffic at scale is like trying to find a specific grain of sand on a beach. We're talking about:

• Thousands to millions of DNS packets
• Each packet between 50-500 bytes (responses are larger depending on records)
• An average user generating around 1,000 DNS requests per day
• Multiply that by thousands of users...

You get the picture. Manual analysis? Forget about it.

Python to the Rescue: Building Tools on the Fly

This is where years of combining networking knowledge with programming skills paid off. I whipped up a couple of Python scripts for DNS validation and verification.

The secret weapon? The pyshark module—a Python wrapper for Wireshark's packet dissection capabilities. It can read and analyze PCAP files with the same power as Wireshark, but programmable.

Here's what the scripts did:

1. Automated packet filtering - Extracted only relevant DNS traffic
2. Pattern recognition - Identified timeout patterns and failed queries
3. Correlation analysis - Matched requests with responses (or lack thereof)
4. Statistical analysis - Generated reports on failure rates by server, query type, and time

What would have taken days of manual analysis was reduced to hours. The scripts churned through millions of packets, identifying patterns that human eyes would have missed.

The Root Cause: A Symphony of Failures

After hours of analysis, the picture became clear. It wasn't just one issue—it was a cascade of problems:

1. DNS server overload - The primary DNS server was hitting CPU limits during peak times
2. Firewall state table exhaustion - DNS queries were creating more states than the firewall could handle
3. Network packet loss - Intermittent loss on specific paths was causing retransmissions
4. Application behavior - Some apps weren't handling DNS timeouts gracefully, creating retry storms

Each team had been right about their piece. But nobody had connected the dots.

The Fix: Coordination Over Isolation

Once we had the full picture, the fix was straightforward:

1. Load balance DNS queries across multiple servers
2. Increase firewall state table limits and optimize timeout values
3. Identify and fix the network path causing packet loss
4. Work with app teams to implement proper DNS timeout handling

Total time to implement once we knew the problems? 2 hours. Time spent pointing fingers before that? Days.

Lessons Learned: For My Fellow Engineers

1. Don't Be Afraid to Step Up

When you see a problem spiraling out of control, take ownership. Your customer will appreciate it, and you'll learn more in those pressure-cooker moments than in months of routine work.

2. Break Down the Silos

The biggest problems often occur at the intersections between teams. Be the person who speaks multiple languages—network, security, systems, and application.

3. Automate the Mundane

Those Python scripts? They're now part of the customer's permanent troubleshooting toolkit. What started as a crisis response became a long-term asset.

4. Make Troubleshooting a Core Skill

It's not just about knowing how things work when they're running smoothly. Real expertise comes from understanding failure modes and having the tools to diagnose them quickly.

DNS 101: Why It's the Hidden Critical Infrastructure

For those who might be thinking "it's just DNS," let me paint you a picture:

DNS is like the phone book of the internet. Every time you:

• Open a website
• Send an email
• Connect to an API
• Use a cloud service
• Launch a mobile app

You're making DNS queries. No DNS = No connection. It's that simple.

Quick DNS Facts That Matter:

• Average query size: 50-500 bytes (tiny, but mighty)
• Queries per user per day: ~1,000 (and growing)
• Typical timeout: 2-5 seconds (an eternity in computer time)
• Impact of 1% failure rate: 10 failed connections per user per day

Now multiply that by thousands of users, and you see why DNS problems escalate so quickly.

The Python Toolkit: What I Built and Why

Here's a simplified version of what those scripts did:

# DNS Packet Analysis Framework
# 1. Filter DNS packets from massive PCAPs
# 2. Identify timeout patterns
# 3. Correlate requests with responses
# 4. Generate actionable reports

import pyshark
from collections import defaultdict
import statistics

def analyze_dns_health(pcap_file):
    """
    Analyzes DNS packet capture for health metrics
    """
    dns_requests = {}
    dns_responses = {}
    timeout_threshold = 5.0  # seconds
    
    # Read packets
    cap = pyshark.FileCapture(pcap_file, 
                             display_filter='dns')
    
    for packet in cap:
        if packet.dns.flags_response == '0':
            # It's a query
            dns_requests[packet.dns.id] = {
                'time': float(packet.sniff_timestamp),
                'query': packet.dns.qry_name
            }
        else:
            # It's a response
            dns_responses[packet.dns.id] = {
                'time': float(packet.sniff_timestamp),
                'response': packet.dns.flags_rcode
            }
    
    # Find timeouts
    timeouts = []
    for req_id, req_data in dns_requests.items():
        if req_id not in dns_responses:
            timeouts.append(req_data['query'])
    
    return {
        'total_queries': len(dns_requests),
        'total_responses': len(dns_responses),
        'timeout_count': len(timeouts),
        'timeout_rate': len(timeouts) / len(dns_requests) * 100
    }

This is simplified, but you get the idea. The real scripts handled edge cases, multiple DNS servers, and generated visual reports.

The Human Side: Why This Matters

At the end of the day, it's not about being a hero. It's about caring enough to dive into the mess when others won't. It's about seeing the bigger picture when everyone else is focused on their piece.

Every outage has real people behind it:

• The IT manager getting calls from angry executives
• The support team dealing with frustrated users
• The business losing revenue every minute
• The customers who can't do their jobs

When you remember that, stepping up isn't optional—it's essential.

Your Turn: Share Your War Stories

Have you ever had to step up and take charge of a tough situation when no one else would?

Maybe it was a DNS meltdown like mine. Maybe it was a network loop bringing down a data center. Maybe it was a security breach on a holiday weekend.

How did it turn out? What did you learn? What tools did you build or wish you had?

Drop a comment below. Let's learn from each other's battle scars.

One Final Thought

DNS might not be as glamorous as routing protocols or as exciting as new SDN technologies. But when it breaks, everything breaks.

Respect the fundamentals. Master the basics. And always, always be ready to step up when nobody else will.

Because that's what separates good engineers from great ones.

P.S. - If you're interested in the Python scripts I mentioned, reach out. Always happy to share tools that make our lives easier. We're all in this together.